diff --git a/tests/wpt/meta-legacy-layout/css/compositing/mix-blend-mode/mix-blend-mode-video.html.ini b/tests/wpt/meta-legacy-layout/css/compositing/mix-blend-mode/mix-blend-mode-video.html.ini
deleted file mode 100644
index 6c64ea15c62..00000000000
--- a/tests/wpt/meta-legacy-layout/css/compositing/mix-blend-mode/mix-blend-mode-video.html.ini
+++ /dev/null
@@ -1,3 +0,0 @@
-[mix-blend-mode-video.html]
-  type: reftest
-  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-animations/display-none-prevents-starting-in-subtree.html.ini b/tests/wpt/meta-legacy-layout/css/css-animations/display-none-prevents-starting-in-subtree.html.ini
new file mode 100644
index 00000000000..612a75448bb
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-animations/display-none-prevents-starting-in-subtree.html.ini
@@ -0,0 +1,3 @@
+[display-none-prevents-starting-in-subtree.html]
+  [Elements in a "display: none" tree cannot start CSS Animations.]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-fonts/generic-family-keywords-001.html.ini b/tests/wpt/meta-legacy-layout/css/css-fonts/generic-family-keywords-001.html.ini
index 07b3a85a5a5..185d50ed83a 100644
--- a/tests/wpt/meta-legacy-layout/css/css-fonts/generic-family-keywords-001.html.ini
+++ b/tests/wpt/meta-legacy-layout/css/css-fonts/generic-family-keywords-001.html.ini
@@ -5,15 +5,9 @@
   [@font-face matching for quoted and unquoted sans-serif]
     expected: FAIL
 
-  [@font-face matching for quoted and unquoted fantasy]
-    expected: FAIL
-
   [@font-face matching for quoted and unquoted monospace]
     expected: FAIL
 
-  [@font-face matching for quoted and unquoted system-ui]
-    expected: FAIL
-
   [@font-face matching for quoted and unquoted emoji]
     expected: FAIL
 
@@ -32,8 +26,5 @@
   [@font-face matching for quoted and unquoted ui-monospace]
     expected: FAIL
 
-  [@font-face matching for quoted and unquoted cursive]
-    expected: FAIL
-
   [@font-face matching for quoted and unquoted ui-serif]
     expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-fonts/parsing/font-family-valid.html.ini b/tests/wpt/meta-legacy-layout/css/css-fonts/parsing/font-family-valid.html.ini
deleted file mode 100644
index b17ac3de579..00000000000
--- a/tests/wpt/meta-legacy-layout/css/css-fonts/parsing/font-family-valid.html.ini
+++ /dev/null
@@ -1,3 +0,0 @@
-[font-family-valid.html]
-  [e.style['font-family'\] = "System-UI" should set the property value]
-    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-fonts/system-ui-ar.html.ini b/tests/wpt/meta-legacy-layout/css/css-fonts/system-ui-ar.html.ini
deleted file mode 100644
index d334315178a..00000000000
--- a/tests/wpt/meta-legacy-layout/css/css-fonts/system-ui-ar.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[system-ui-ar.html]
-  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-fonts/system-ui-mixed.html.ini b/tests/wpt/meta-legacy-layout/css/css-fonts/system-ui-mixed.html.ini
deleted file mode 100644
index 9965271ed89..00000000000
--- a/tests/wpt/meta-legacy-layout/css/css-fonts/system-ui-mixed.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[system-ui-mixed.html]
-  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-fonts/system-ui-ur.html.ini b/tests/wpt/meta-legacy-layout/css/css-fonts/system-ui-ur.html.ini
deleted file mode 100644
index d9e58e116a2..00000000000
--- a/tests/wpt/meta-legacy-layout/css/css-fonts/system-ui-ur.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[system-ui-ur.html]
-  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-fonts/system-ui.html.ini b/tests/wpt/meta-legacy-layout/css/css-fonts/system-ui.html.ini
deleted file mode 100644
index fc1193a36c4..00000000000
--- a/tests/wpt/meta-legacy-layout/css/css-fonts/system-ui.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[system-ui.html]
-  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-022.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-022.tentative.html.ini
new file mode 100644
index 00000000000..b9715bdcbcf
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-022.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-022.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-023.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-023.tentative.html.ini
new file mode 100644
index 00000000000..4de92d88f8a
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-023.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-023.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-024.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-024.tentative.html.ini
new file mode 100644
index 00000000000..b4f17815816
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-024.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-024.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-025.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-025.tentative.html.ini
new file mode 100644
index 00000000000..21c21386446
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-025.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-025.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-026.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-026.tentative.html.ini
new file mode 100644
index 00000000000..cc760d52775
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-026.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-026.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-027.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-027.tentative.html.ini
new file mode 100644
index 00000000000..72c0f91de75
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-027.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-027.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-017.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-017.tentative.html.ini
new file mode 100644
index 00000000000..50a860f5cff
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-017.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-017.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-018.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-018.tentative.html.ini
new file mode 100644
index 00000000000..cc12506ab76
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-018.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-018.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-019.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-019.tentative.html.ini
new file mode 100644
index 00000000000..0eb22442455
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-019.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-019.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-020.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-020.tentative.html.ini
new file mode 100644
index 00000000000..c4a3171091e
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-020.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-020.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-021.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-021.tentative.html.ini
new file mode 100644
index 00000000000..ec0dd2607ab
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-021.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-021.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-022.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-022.tentative.html.ini
new file mode 100644
index 00000000000..a4378bd91ec
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-022.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-022.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-023.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-023.tentative.html.ini
new file mode 100644
index 00000000000..be570e7abe9
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-023.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-023.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-024.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-024.tentative.html.ini
new file mode 100644
index 00000000000..cfa4a650a3a
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-024.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-024.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-025.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-025.tentative.html.ini
new file mode 100644
index 00000000000..c1786082c26
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-025.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-025.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-026.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-026.tentative.html.ini
new file mode 100644
index 00000000000..0ee497e3bcd
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-026.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-026.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-027.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-027.tentative.html.ini
new file mode 100644
index 00000000000..30b109549c3
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-027.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-027.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-028.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-028.tentative.html.ini
new file mode 100644
index 00000000000..465e96a5404
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-028.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-028.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-029.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-029.tentative.html.ini
new file mode 100644
index 00000000000..3f6611a7627
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-029.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-029.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-030.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-030.tentative.html.ini
new file mode 100644
index 00000000000..4fdd099a51a
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-030.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-030.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-031.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-031.tentative.html.ini
new file mode 100644
index 00000000000..2c233b1cacc
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-031.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-031.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-032.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-032.tentative.html.ini
new file mode 100644
index 00000000000..00093f16b28
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-auto-032.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-032.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-with-abspos-012.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-with-abspos-012.tentative.html.ini
new file mode 100644
index 00000000000..2f746ad56f3
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-with-abspos-012.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-with-abspos-012.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-with-abspos-013.tentative.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-with-abspos-013.tentative.html.ini
new file mode 100644
index 00000000000..f710874fa75
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/line-clamp/line-clamp-with-abspos-013.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-with-abspos-013.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-overflow/overflow-video.html.ini b/tests/wpt/meta-legacy-layout/css/css-overflow/overflow-video.html.ini
new file mode 100644
index 00000000000..1d0a9d754d6
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-overflow/overflow-video.html.ini
@@ -0,0 +1,2 @@
+[overflow-video.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-transforms/transform-input-017.html.ini b/tests/wpt/meta-legacy-layout/css/css-transforms/transform-input-017.html.ini
index b6c96fff2e3..66db39edcb9 100644
--- a/tests/wpt/meta-legacy-layout/css/css-transforms/transform-input-017.html.ini
+++ b/tests/wpt/meta-legacy-layout/css/css-transforms/transform-input-017.html.ini
@@ -1,5 +1,3 @@
 [transform-input-017.html]
   type: reftest
   bug: https://github.com/servo/servo/issues/21092
-  expected:
-    if os == "linux": FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-transforms/transform-input-018.html.ini b/tests/wpt/meta-legacy-layout/css/css-transforms/transform-input-018.html.ini
index c90ddb7f550..894e4cca09e 100644
--- a/tests/wpt/meta-legacy-layout/css/css-transforms/transform-input-018.html.ini
+++ b/tests/wpt/meta-legacy-layout/css/css-transforms/transform-input-018.html.ini
@@ -1,4 +1,3 @@
 [transform-input-018.html]
   type: reftest
   bug: https://github.com/servo/servo/issues/21092
-  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-transitions/pseudo-element-transform.html.ini b/tests/wpt/meta-legacy-layout/css/css-transitions/pseudo-element-transform.html.ini
new file mode 100644
index 00000000000..67df2295e2e
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-transitions/pseudo-element-transform.html.ini
@@ -0,0 +1,2 @@
+[pseudo-element-transform.html]
+  expected: TIMEOUT
diff --git a/tests/wpt/meta-legacy-layout/css/css-transitions/transitions-retarget.html.ini b/tests/wpt/meta-legacy-layout/css/css-transitions/transitions-retarget.html.ini
new file mode 100644
index 00000000000..72d9f209146
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-transitions/transitions-retarget.html.ini
@@ -0,0 +1,3 @@
+[transitions-retarget.html]
+  [Retargeting a transition should cause the old transition to be cancelled]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-values/calc-size/animation/interpolate-size-interpolation.html.ini b/tests/wpt/meta-legacy-layout/css/css-values/calc-size/animation/interpolate-size-interpolation.html.ini
new file mode 100644
index 00000000000..3c23c23b88a
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-values/calc-size/animation/interpolate-size-interpolation.html.ini
@@ -0,0 +1,2 @@
+[interpolate-size-interpolation.html]
+  expected: ERROR
diff --git a/tests/wpt/meta-legacy-layout/css/css-values/calc-size/interpolate-size-computed.html.ini b/tests/wpt/meta-legacy-layout/css/css-values/calc-size/interpolate-size-computed.html.ini
new file mode 100644
index 00000000000..ae2404f8a21
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-values/calc-size/interpolate-size-computed.html.ini
@@ -0,0 +1,6 @@
+[interpolate-size-computed.html]
+  [Property interpolate-size value 'numeric-only']
+    expected: FAIL
+
+  [Property interpolate-size value 'allow-keywords']
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/css-values/calc-size/interpolate-size-parsing.html.ini b/tests/wpt/meta-legacy-layout/css/css-values/calc-size/interpolate-size-parsing.html.ini
new file mode 100644
index 00000000000..61bfc890ca0
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/css/css-values/calc-size/interpolate-size-parsing.html.ini
@@ -0,0 +1,6 @@
+[interpolate-size-parsing.html]
+  [e.style['interpolate-size'\] = "numeric-only" should set the property value]
+    expected: FAIL
+
+  [e.style['interpolate-size'\] = "allow-keywords" should set the property value]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/css/cssom-view/MediaQueryListEvent.html.ini b/tests/wpt/meta-legacy-layout/css/cssom-view/MediaQueryListEvent.html.ini
index 5276a0fea9f..0fb25fc1fba 100644
--- a/tests/wpt/meta-legacy-layout/css/cssom-view/MediaQueryListEvent.html.ini
+++ b/tests/wpt/meta-legacy-layout/css/cssom-view/MediaQueryListEvent.html.ini
@@ -1,2 +1,7 @@
 [MediaQueryListEvent.html]
   expected: TIMEOUT
+  [argument of onchange]
+    expected: TIMEOUT
+
+  [constructor of "change" event]
+    expected: NOTRUN
diff --git a/tests/wpt/meta-legacy-layout/css/selectors/media/media-playback-state.html.ini b/tests/wpt/meta-legacy-layout/css/selectors/media/media-playback-state.html.ini
index 5ece18229f8..0d01e57bd5f 100644
--- a/tests/wpt/meta-legacy-layout/css/selectors/media/media-playback-state.html.ini
+++ b/tests/wpt/meta-legacy-layout/css/selectors/media/media-playback-state.html.ini
@@ -1,4 +1,5 @@
 [media-playback-state.html]
+  expected: TIMEOUT
   [Test :pseudo-class syntax is supported without throwing a SyntaxError]
     expected: FAIL
 
@@ -6,7 +7,7 @@
     expected: FAIL
 
   [Test :paused pseudo-classes]
-    expected: FAIL
+    expected: TIMEOUT
 
   [Test :seeking pseudo-class]
-    expected: FAIL
+    expected: NOTRUN
diff --git a/tests/wpt/meta-legacy-layout/custom-elements/CustomElementRegistry-getName.html.ini b/tests/wpt/meta-legacy-layout/custom-elements/CustomElementRegistry-getName.html.ini
deleted file mode 100644
index cb43c25dc3a..00000000000
--- a/tests/wpt/meta-legacy-layout/custom-elements/CustomElementRegistry-getName.html.ini
+++ /dev/null
@@ -1,9 +0,0 @@
-[CustomElementRegistry-getName.html]
-  [customElements.getName must return null when the registry does not contain an entry with the given constructor]
-    expected: FAIL
-
-  [customElements.getName returns the name of the entry with the given constructor when there is a matching entry.]
-    expected: FAIL
-
-  [customElements.getName returns the name of the entry with the given customized built in constructor when there is a matching entry.]
-    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/dom/observable/tentative/observable-constructor.any.js.ini b/tests/wpt/meta-legacy-layout/dom/observable/tentative/observable-constructor.any.js.ini
index 3997fbb757a..8221c036594 100644
--- a/tests/wpt/meta-legacy-layout/dom/observable/tentative/observable-constructor.any.js.ini
+++ b/tests/wpt/meta-legacy-layout/dom/observable/tentative/observable-constructor.any.js.ini
@@ -110,6 +110,15 @@
   [Subscriber#error() value is stored as Subscriber's AbortSignal's reason]
     expected: FAIL
 
+  [Teardowns are called in upstream->downstream order on consumer-initiated unsubscription]
+    expected: FAIL
+
+  [Teardowns are called in downstream->upstream order on consumer-initiated unsubscription with pre-aborted Signal]
+    expected: FAIL
+
+  [Producer-initiated unsubscription in a downstream Observable fires abort events before each teardown, in downstream->upstream order]
+    expected: FAIL
+
 
 [observable-constructor.any.html]
   [Observable constructor]
@@ -222,3 +231,12 @@
 
   [Subscriber#error() value is stored as Subscriber's AbortSignal's reason]
     expected: FAIL
+
+  [Teardowns are called in upstream->downstream order on consumer-initiated unsubscription]
+    expected: FAIL
+
+  [Teardowns are called in downstream->upstream order on consumer-initiated unsubscription with pre-aborted Signal]
+    expected: FAIL
+
+  [Producer-initiated unsubscription in a downstream Observable fires abort events before each teardown, in downstream->upstream order]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/fetch/metadata/generated/css-font-face.sub.tentative.html.ini b/tests/wpt/meta-legacy-layout/fetch/metadata/generated/css-font-face.sub.tentative.html.ini
index 6eebff7271d..349ae97cf12 100644
--- a/tests/wpt/meta-legacy-layout/fetch/metadata/generated/css-font-face.sub.tentative.html.ini
+++ b/tests/wpt/meta-legacy-layout/fetch/metadata/generated/css-font-face.sub.tentative.html.ini
@@ -32,8 +32,5 @@
   [sec-fetch-dest - Not sent to non-trustworthy same-site destination]
     expected: FAIL
 
-  [sec-fetch-user - Not sent to non-trustworthy same-site destination]
-    expected: FAIL
-
   [sec-fetch-user - Not sent to non-trustworthy cross-site destination]
     expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/fetch/orb/tentative/known-mime-type.sub.any.js.ini b/tests/wpt/meta-legacy-layout/fetch/orb/tentative/known-mime-type.sub.any.js.ini
index b05b6f9e2bd..cae3ce43d64 100644
--- a/tests/wpt/meta-legacy-layout/fetch/orb/tentative/known-mime-type.sub.any.js.ini
+++ b/tests/wpt/meta-legacy-layout/fetch/orb/tentative/known-mime-type.sub.any.js.ini
@@ -27,101 +27,26 @@
   [ORB should block opaque text/plain: fetch(..., {mode: "no-cors"})]
     expected: FAIL
 
-  [ORB should block opaque text/plain: <audio src=...>]
-    expected: TIMEOUT
-
-  [ORB should block opaque text/plain: <video src=...>]
-    expected: NOTRUN
-
   [ORB should block opaque text/plain: <script src=...>]
-    expected: NOTRUN
+    expected: FAIL
 
   [ORB should block opaque application/json (non-empty): fetch(..., {mode: "no-cors"})]
-    expected: NOTRUN
-
-  [ORB should block opaque application/json (non-empty): <img src=...>]
-    expected: NOTRUN
-
-  [ORB should block opaque application/json (non-empty): <audio src=...>]
-    expected: NOTRUN
-
-  [ORB should block opaque application/json (non-empty): <video src=...>]
-    expected: NOTRUN
+    expected: FAIL
 
   [ORB should block opaque application/json (non-empty): <script src=...>]
-    expected: NOTRUN
+    expected: FAIL
 
   [ORB should block opaque application/json (empty): fetch(..., {mode: "no-cors"})]
-    expected: NOTRUN
-
-  [ORB should block opaque application/json (empty): <img src=...>]
-    expected: NOTRUN
-
-  [ORB should block opaque application/json (empty): <audio src=...>]
-    expected: NOTRUN
-
-  [ORB should block opaque application/json (empty): <video src=...>]
-    expected: NOTRUN
+    expected: FAIL
 
   [ORB should block opaque application/json (empty): <script src=...>]
-    expected: NOTRUN
+    expected: FAIL
 
   [ORB should block opaque application/json which contains non ascii characters: fetch(..., {mode: "no-cors"})]
-    expected: NOTRUN
-
-  [ORB should block opaque application/json which contains non ascii characters: <img src=...>]
-    expected: NOTRUN
-
-  [ORB should block opaque application/json which contains non ascii characters: <audio src=...>]
-    expected: NOTRUN
-
-  [ORB should block opaque application/json which contains non ascii characters: <video src=...>]
-    expected: NOTRUN
+    expected: FAIL
 
   [ORB should block opaque application/json which contains non ascii characters: <script src=...>]
-    expected: NOTRUN
-
-  [ORB shouldn't block opaque image/png: fetch(..., {mode: "no-cors"})]
-    expected: NOTRUN
-
-  [ORB shouldn't block opaque image/png: <img src=...>]
-    expected: NOTRUN
-
-  [ORB shouldn't block opaque text/javascript: fetch(..., {mode: "no-cors"})]
-    expected: NOTRUN
-
-  [ORB shouldn't block opaque text/javascript: <script src=...>]
-    expected: NOTRUN
-
-  [ORB shouldn't block opaque text/javascript (utf16 encoded with BOM): fetch(..., {mode: "no-cors"})]
-    expected: NOTRUN
-
-  [ORB shouldn't block opaque text/javascript (utf16 encoded with BOM): <script src=...>]
-    expected: NOTRUN
-
-  [ORB shouldn't block opaque text/javascript (utf16 encoded without BOM but charset is provided in content-type): fetch(..., {mode: "no-cors"})]
-    expected: NOTRUN
-
-  [ORB shouldn't block opaque text/javascript (utf16 encoded without BOM but charset is provided in content-type): <script src=...>]
-    expected: NOTRUN
-
-  [ORB shouldn't block opaque text/javascript (iso-8559-1 encoded): fetch(..., {mode: "no-cors"})]
-    expected: NOTRUN
-
-  [ORB shouldn't block opaque text/javascript (iso-8559-1 encoded): <script src=...>]
-    expected: NOTRUN
-
-  [ORB shouldn't block text/javascript with valid asm.js: fetch(..., {mode: "no-cors"})]
-    expected: NOTRUN
-
-  [ORB shouldn't block text/javascript with valid asm.js: <script src=...>]
-    expected: NOTRUN
-
-  [ORB shouldn't block text/javascript with invalid asm.js: fetch(..., {mode: "no-cors"})]
-    expected: NOTRUN
-
-  [ORB shouldn't block text/javascript with invalid asm.js: <script src=...>]
-    expected: NOTRUN
+    expected: FAIL
 
 
 [known-mime-type.sub.any.worker.html]
diff --git a/tests/wpt/meta-legacy-layout/fetch/orb/tentative/nosniff.sub.any.js.ini b/tests/wpt/meta-legacy-layout/fetch/orb/tentative/nosniff.sub.any.js.ini
index d922a3ef99a..a38b187f919 100644
--- a/tests/wpt/meta-legacy-layout/fetch/orb/tentative/nosniff.sub.any.js.ini
+++ b/tests/wpt/meta-legacy-layout/fetch/orb/tentative/nosniff.sub.any.js.ini
@@ -1,5 +1,5 @@
 [nosniff.sub.any.html]
-  expected: TIMEOUT
+  expected: ERROR
   [ORB should block opaque text/plain with nosniff]
     expected: FAIL
 
@@ -12,50 +12,20 @@
   [ORB should block opaque text/plain with nosniff: fetch(..., {mode: "no-cors"})]
     expected: FAIL
 
-  [ORB should block opaque text/plain with nosniff: <audio src=...>]
-    expected: TIMEOUT
-
-  [ORB should block opaque text/plain with nosniff: <video src=...>]
-    expected: NOTRUN
-
   [ORB should block opaque text/plain with nosniff: <script src=...>]
-    expected: NOTRUN
+    expected: FAIL
 
   [ORB should block opaque-response-blocklisted MIME type with nosniff: fetch(..., {mode: "no-cors"})]
-    expected: NOTRUN
-
-  [ORB should block opaque-response-blocklisted MIME type with nosniff: <img src=...>]
-    expected: NOTRUN
-
-  [ORB should block opaque-response-blocklisted MIME type with nosniff: <audio src=...>]
-    expected: NOTRUN
-
-  [ORB should block opaque-response-blocklisted MIME type with nosniff: <video src=...>]
-    expected: NOTRUN
+    expected: FAIL
 
   [ORB should block opaque-response-blocklisted MIME type with nosniff: <script src=...>]
-    expected: NOTRUN
+    expected: FAIL
 
   [ORB should block opaque response with empty Content-Type and nosniff: fetch(..., {mode: "no-cors"})]
-    expected: NOTRUN
-
-  [ORB should block opaque response with empty Content-Type and nosniff: <img src=...>]
-    expected: NOTRUN
-
-  [ORB should block opaque response with empty Content-Type and nosniff: <audio src=...>]
-    expected: NOTRUN
-
-  [ORB should block opaque response with empty Content-Type and nosniff: <video src=...>]
-    expected: NOTRUN
+    expected: FAIL
 
   [ORB should block opaque response with empty Content-Type and nosniff: <script src=...>]
-    expected: NOTRUN
-
-  [ORB shouldn't block opaque image with empty Content-Type and nosniff: fetch(..., {mode: "no-cors"})]
-    expected: NOTRUN
-
-  [ORB shouldn't block opaque image with empty Content-Type and nosniff: <img src=...>]
-    expected: NOTRUN
+    expected: FAIL
 
 
 [nosniff.sub.any.worker.html]
diff --git a/tests/wpt/meta-legacy-layout/fetch/orb/tentative/status.sub.any.js.ini b/tests/wpt/meta-legacy-layout/fetch/orb/tentative/status.sub.any.js.ini
index 332ee884317..c0940d7ac48 100644
--- a/tests/wpt/meta-legacy-layout/fetch/orb/tentative/status.sub.any.js.ini
+++ b/tests/wpt/meta-legacy-layout/fetch/orb/tentative/status.sub.any.js.ini
@@ -13,7 +13,7 @@
 
 
 [status.sub.any.html]
-  expected: TIMEOUT
+  expected: ERROR
   [ORB should block opaque-response-blocklisted MIME type with status 206]
     expected: FAIL
 
@@ -23,26 +23,8 @@
   [ORB should block opaque-response-blocklisted MIME type with status 206: fetch(..., {mode: "no-cors"})]
     expected: FAIL
 
-  [ORB should block opaque-response-blocklisted MIME type with status 206: <audio src=...>]
-    expected: TIMEOUT
-
-  [ORB should block opaque-response-blocklisted MIME type with status 206: <video src=...>]
-    expected: NOTRUN
-
   [ORB should block opaque-response-blocklisted MIME type with status 206: <script src=...>]
-    expected: NOTRUN
+    expected: FAIL
 
   [ORB should block opaque response with non-ok status: fetch(..., {mode: "no-cors"})]
-    expected: NOTRUN
-
-  [ORB should block opaque response with non-ok status: <img src=...>]
-    expected: NOTRUN
-
-  [ORB should block opaque response with non-ok status: <audio src=...>]
-    expected: NOTRUN
-
-  [ORB should block opaque response with non-ok status: <video src=...>]
-    expected: NOTRUN
-
-  [ORB should block opaque response with non-ok status: <script src=...>]
-    expected: NOTRUN
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/fetch/range/non-matching-range-response.html.ini b/tests/wpt/meta-legacy-layout/fetch/range/non-matching-range-response.html.ini
new file mode 100644
index 00000000000..0e0aa9e5c23
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/fetch/range/non-matching-range-response.html.ini
@@ -0,0 +1,3 @@
+[non-matching-range-response.html]
+  [Range response out of range of request should succeed]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/browsers/windows/post-message/first-party-to-third-party-cross-partition-cross-origin.sub.html.ini b/tests/wpt/meta-legacy-layout/html/browsers/windows/post-message/first-party-to-third-party-cross-partition-cross-origin.sub.html.ini
deleted file mode 100644
index 283c44174a7..00000000000
--- a/tests/wpt/meta-legacy-layout/html/browsers/windows/post-message/first-party-to-third-party-cross-partition-cross-origin.sub.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[first-party-to-third-party-cross-partition-cross-origin.sub.html]
-  expected: TIMEOUT
-  [postMessage: First-Party to Third-Party, Cross-Partition, Cross-Origin]
-    expected: TIMEOUT
diff --git a/tests/wpt/meta-legacy-layout/html/browsers/windows/post-message/first-party-to-third-party-cross-partition-same-origin.sub.html.ini b/tests/wpt/meta-legacy-layout/html/browsers/windows/post-message/first-party-to-third-party-cross-partition-same-origin.sub.html.ini
deleted file mode 100644
index 762a134ed26..00000000000
--- a/tests/wpt/meta-legacy-layout/html/browsers/windows/post-message/first-party-to-third-party-cross-partition-same-origin.sub.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[first-party-to-third-party-cross-partition-same-origin.sub.html]
-  expected: TIMEOUT
-  [postMessage: First-Party to Third-Party, Cross-Partition, Same-Origin]
-    expected: TIMEOUT
diff --git a/tests/wpt/meta-legacy-layout/html/browsers/windows/post-message/third-party-to-third-party-cross-partition-cross-origin.sub.html.ini b/tests/wpt/meta-legacy-layout/html/browsers/windows/post-message/third-party-to-third-party-cross-partition-cross-origin.sub.html.ini
deleted file mode 100644
index e211e6be83a..00000000000
--- a/tests/wpt/meta-legacy-layout/html/browsers/windows/post-message/third-party-to-third-party-cross-partition-cross-origin.sub.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[third-party-to-third-party-cross-partition-cross-origin.sub.html]
-  expected: TIMEOUT
-  [postMessage: Third-Party to Third-Party, Cross-Partition, Cross-Origin]
-    expected: TIMEOUT
diff --git a/tests/wpt/meta-legacy-layout/html/browsers/windows/post-message/third-party-to-third-party-cross-partition-same-origin.sub.html.ini b/tests/wpt/meta-legacy-layout/html/browsers/windows/post-message/third-party-to-third-party-cross-partition-same-origin.sub.html.ini
deleted file mode 100644
index 488c6bd15d4..00000000000
--- a/tests/wpt/meta-legacy-layout/html/browsers/windows/post-message/third-party-to-third-party-cross-partition-same-origin.sub.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[third-party-to-third-party-cross-partition-same-origin.sub.html]
-  expected: TIMEOUT
-  [postMessage: Third-Party to Third-Party, Cross-Partition, Same-Origin]
-    expected: TIMEOUT
diff --git a/tests/wpt/meta-legacy-layout/html/browsers/windows/post-message/third-party-to-third-party-same-partition.sub.html.ini b/tests/wpt/meta-legacy-layout/html/browsers/windows/post-message/third-party-to-third-party-same-partition.sub.html.ini
deleted file mode 100644
index 30607f12f29..00000000000
--- a/tests/wpt/meta-legacy-layout/html/browsers/windows/post-message/third-party-to-third-party-same-partition.sub.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[third-party-to-third-party-same-partition.sub.html]
-  expected: TIMEOUT
-  [postMessage: Third-Party to Third-Party, Same-Partition]
-    expected: TIMEOUT
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/element/manual/imagebitmap/createImageBitmap-colorSpaceConversion.html.ini b/tests/wpt/meta-legacy-layout/html/canvas/element/manual/imagebitmap/createImageBitmap-colorSpaceConversion.html.ini
index a509d94b8c6..b44bcf4550f 100644
--- a/tests/wpt/meta-legacy-layout/html/canvas/element/manual/imagebitmap/createImageBitmap-colorSpaceConversion.html.ini
+++ b/tests/wpt/meta-legacy-layout/html/canvas/element/manual/imagebitmap/createImageBitmap-colorSpaceConversion.html.ini
@@ -1,4 +1,5 @@
 [createImageBitmap-colorSpaceConversion.html]
+  expected: ERROR
   [createImageBitmap from a bitmap HTMLImageElement, and drawImage on the created ImageBitmap with colorSpaceConversion: none]
     expected: FAIL
 
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/element/manual/imagebitmap/createImageBitmap-serializable.html.ini b/tests/wpt/meta-legacy-layout/html/canvas/element/manual/imagebitmap/createImageBitmap-serializable.html.ini
index 822d86ef159..ea398e580ef 100644
--- a/tests/wpt/meta-legacy-layout/html/canvas/element/manual/imagebitmap/createImageBitmap-serializable.html.ini
+++ b/tests/wpt/meta-legacy-layout/html/canvas/element/manual/imagebitmap/createImageBitmap-serializable.html.ini
@@ -1,5 +1,5 @@
 [createImageBitmap-serializable.html]
-  expected: TIMEOUT
+  expected: ERROR
   [Serialize ImageBitmap created from a vector SVGImageElement]
     expected: NOTRUN
 
@@ -35,4 +35,3 @@
 
   [Serialize ImageBitmap created from a bitmap SVGImageElement]
     expected: TIMEOUT
-
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/element/text/2d.text.measure.caret-position-edge-cases.tentative.html.ini b/tests/wpt/meta-legacy-layout/html/canvas/element/text/2d.text.measure.caret-position-edge-cases.tentative.html.ini
new file mode 100644
index 00000000000..751ca58fa7e
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/html/canvas/element/text/2d.text.measure.caret-position-edge-cases.tentative.html.ini
@@ -0,0 +1,3 @@
+[2d.text.measure.caret-position-edge-cases.tentative.html]
+  [Test the edge cases for caretPositionFromPoint, where the point is at the edge of glyph and at the midpoint.]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/element/text/2d.text.measure.caret-position-edges.tentative.html.ini b/tests/wpt/meta-legacy-layout/html/canvas/element/text/2d.text.measure.caret-position-edges.tentative.html.ini
new file mode 100644
index 00000000000..a8f84833ae9
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/html/canvas/element/text/2d.text.measure.caret-position-edges.tentative.html.ini
@@ -0,0 +1,30 @@
+[2d.text.measure.caret-position-edges.tentative.html]
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align left.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align left.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align center.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align center.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align right.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align right.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align start.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align start.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align end.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align end.]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/element/text/2d.text.measure.caret-position.tentative.html.ini b/tests/wpt/meta-legacy-layout/html/canvas/element/text/2d.text.measure.caret-position.tentative.html.ini
new file mode 100644
index 00000000000..2b7dea3b3b2
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/html/canvas/element/text/2d.text.measure.caret-position.tentative.html.ini
@@ -0,0 +1,120 @@
+[2d.text.measure.caret-position.tentative.html]
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 10px letter spacing and directional-override.]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/element/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.html.ini b/tests/wpt/meta-legacy-layout/html/canvas/element/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.html.ini
new file mode 100644
index 00000000000..26263231bef
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/html/canvas/element/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.html.ini
@@ -0,0 +1,2 @@
+[2d.text.measure.getActualBoundingBox-exceptions.tentative.html]
+  expected: ERROR
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/element/text/2d.text.measure.getActualBoundingBox-full-text.tentative.html.ini b/tests/wpt/meta-legacy-layout/html/canvas/element/text/2d.text.measure.getActualBoundingBox-full-text.tentative.html.ini
new file mode 100644
index 00000000000..174591cf89f
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/html/canvas/element/text/2d.text.measure.getActualBoundingBox-full-text.tentative.html.ini
@@ -0,0 +1,12 @@
+[2d.text.measure.getActualBoundingBox-full-text.tentative.html]
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction ltr and no-directional-override]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction rtl and no-directional-override]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction ltr and directional-override]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction rtl and directional-override]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/element/text/2d.text.measure.getActualBoundingBox.tentative.html.ini b/tests/wpt/meta-legacy-layout/html/canvas/element/text/2d.text.measure.getActualBoundingBox.tentative.html.ini
new file mode 100644
index 00000000000..fbde9c92f4b
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/html/canvas/element/text/2d.text.measure.getActualBoundingBox.tentative.html.ini
@@ -0,0 +1,18 @@
+[2d.text.measure.getActualBoundingBox.tentative.html]
+  [Test TextMetrics::getActualBoundingBox(), with text align left , and 0px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align center , and 0px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align right , and 0px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align left , and 10px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align center , and 10px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align right , and 10px letter spacing.]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/element/text/2d.text.measure.selection-rects.tentative.html.ini b/tests/wpt/meta-legacy-layout/html/canvas/element/text/2d.text.measure.selection-rects.tentative.html.ini
index bd83dffdce1..26358feced0 100644
--- a/tests/wpt/meta-legacy-layout/html/canvas/element/text/2d.text.measure.selection-rects.tentative.html.ini
+++ b/tests/wpt/meta-legacy-layout/html/canvas/element/text/2d.text.measure.selection-rects.tentative.html.ini
@@ -1,3 +1,75 @@
 [2d.text.measure.selection-rects.tentative.html]
   [Check that TextMetrics::getSelectionRects() matches its DOM equivalent.]
     expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 10px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 10px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 10px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 10px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 10px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 10px letter spacing, and directional-override.]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/offscreen/fill-and-stroke-styles/2d.gradient.interpolate.zerosize.fillText.html.ini b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/fill-and-stroke-styles/2d.gradient.interpolate.zerosize.fillText.html.ini
deleted file mode 100644
index 0a8b4be90d6..00000000000
--- a/tests/wpt/meta-legacy-layout/html/canvas/offscreen/fill-and-stroke-styles/2d.gradient.interpolate.zerosize.fillText.html.ini
+++ /dev/null
@@ -1,3 +0,0 @@
-[2d.gradient.interpolate.zerosize.fillText.html]
-  [OffscreenCanvas test: 2d.gradient.interpolate.zerosize.fillText]
-    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/offscreen/fill-and-stroke-styles/2d.gradient.interpolate.zerosize.fillText.worker.js.ini b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/fill-and-stroke-styles/2d.gradient.interpolate.zerosize.fillText.worker.js.ini
deleted file mode 100644
index 0a6c14e61c4..00000000000
--- a/tests/wpt/meta-legacy-layout/html/canvas/offscreen/fill-and-stroke-styles/2d.gradient.interpolate.zerosize.fillText.worker.js.ini
+++ /dev/null
@@ -1,3 +0,0 @@
-[2d.gradient.interpolate.zerosize.fillText.worker.html]
-  [2d]
-    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/offscreen/reset/2d.reset.render.text.html.ini b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/reset/2d.reset.render.text.html.ini
new file mode 100644
index 00000000000..bab41d308bf
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/reset/2d.reset.render.text.html.ini
@@ -0,0 +1,2 @@
+[2d.reset.render.text.html]
+  expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.caret-position-edge-cases.tentative.html.ini b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.caret-position-edge-cases.tentative.html.ini
new file mode 100644
index 00000000000..751ca58fa7e
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.caret-position-edge-cases.tentative.html.ini
@@ -0,0 +1,3 @@
+[2d.text.measure.caret-position-edge-cases.tentative.html]
+  [Test the edge cases for caretPositionFromPoint, where the point is at the edge of glyph and at the midpoint.]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.caret-position-edge-cases.tentative.worker.js.ini b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.caret-position-edge-cases.tentative.worker.js.ini
new file mode 100644
index 00000000000..5d4cad8801f
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.caret-position-edge-cases.tentative.worker.js.ini
@@ -0,0 +1,3 @@
+[2d.text.measure.caret-position-edge-cases.tentative.worker.html]
+  [Test the edge cases for caretPositionFromPoint, where the point is at the edge of glyph and at the midpoint.]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.caret-position-edges.tentative.html.ini b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.caret-position-edges.tentative.html.ini
new file mode 100644
index 00000000000..a8f84833ae9
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.caret-position-edges.tentative.html.ini
@@ -0,0 +1,30 @@
+[2d.text.measure.caret-position-edges.tentative.html]
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align left.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align left.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align center.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align center.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align right.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align right.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align start.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align start.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align end.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align end.]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.caret-position-edges.tentative.worker.js.ini b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.caret-position-edges.tentative.worker.js.ini
new file mode 100644
index 00000000000..08ebd3f82f7
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.caret-position-edges.tentative.worker.js.ini
@@ -0,0 +1,30 @@
+[2d.text.measure.caret-position-edges.tentative.worker.html]
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align left.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align left.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align center.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align center.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align right.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align right.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align start.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align start.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align end.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align end.]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.caret-position.tentative.html.ini b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.caret-position.tentative.html.ini
new file mode 100644
index 00000000000..2b7dea3b3b2
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.caret-position.tentative.html.ini
@@ -0,0 +1,120 @@
+[2d.text.measure.caret-position.tentative.html]
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 10px letter spacing and directional-override.]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.html.ini b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.html.ini
new file mode 100644
index 00000000000..26263231bef
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.html.ini
@@ -0,0 +1,2 @@
+[2d.text.measure.getActualBoundingBox-exceptions.tentative.html]
+  expected: ERROR
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.worker.js.ini b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.worker.js.ini
new file mode 100644
index 00000000000..615275f70fe
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.worker.js.ini
@@ -0,0 +1,2 @@
+[2d.text.measure.getActualBoundingBox-exceptions.tentative.worker.html]
+  expected: TIMEOUT
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-full-text.tentative.html.ini b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-full-text.tentative.html.ini
new file mode 100644
index 00000000000..174591cf89f
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-full-text.tentative.html.ini
@@ -0,0 +1,12 @@
+[2d.text.measure.getActualBoundingBox-full-text.tentative.html]
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction ltr and no-directional-override]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction rtl and no-directional-override]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction ltr and directional-override]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction rtl and directional-override]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-full-text.tentative.worker.js.ini b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-full-text.tentative.worker.js.ini
new file mode 100644
index 00000000000..2f1f2db1ce6
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-full-text.tentative.worker.js.ini
@@ -0,0 +1,12 @@
+[2d.text.measure.getActualBoundingBox-full-text.tentative.worker.html]
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction ltr and no-directional-override]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction rtl and no-directional-override]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction ltr and directional-override]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction rtl and directional-override]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox.tentative.html.ini b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox.tentative.html.ini
new file mode 100644
index 00000000000..fbde9c92f4b
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox.tentative.html.ini
@@ -0,0 +1,18 @@
+[2d.text.measure.getActualBoundingBox.tentative.html]
+  [Test TextMetrics::getActualBoundingBox(), with text align left , and 0px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align center , and 0px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align right , and 0px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align left , and 10px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align center , and 10px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align right , and 10px letter spacing.]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox.tentative.worker.js.ini b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox.tentative.worker.js.ini
new file mode 100644
index 00000000000..f3cc13a0b5e
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox.tentative.worker.js.ini
@@ -0,0 +1,18 @@
+[2d.text.measure.getActualBoundingBox.tentative.worker.html]
+  [Test TextMetrics::getActualBoundingBox(), with text align left , and 0px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align center , and 0px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align right , and 0px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align left , and 10px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align center , and 10px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align right , and 10px letter spacing.]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.selection-rects.tentative.html.ini b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.selection-rects.tentative.html.ini
index bd83dffdce1..26358feced0 100644
--- a/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.selection-rects.tentative.html.ini
+++ b/tests/wpt/meta-legacy-layout/html/canvas/offscreen/text/2d.text.measure.selection-rects.tentative.html.ini
@@ -1,3 +1,75 @@
 [2d.text.measure.selection-rects.tentative.html]
   [Check that TextMetrics::getSelectionRects() matches its DOM equivalent.]
     expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 10px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 10px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 10px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 10px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 10px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 10px letter spacing, and directional-override.]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/dom/elements/global-attributes/cdata-dir_auto.html.ini b/tests/wpt/meta-legacy-layout/html/dom/elements/global-attributes/cdata-dir_auto.html.ini
new file mode 100644
index 00000000000..e21e72894e5
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/html/dom/elements/global-attributes/cdata-dir_auto.html.ini
@@ -0,0 +1,12 @@
+[cdata-dir_auto.html]
+  [Content of CDATA is ignored for dir=auto in html document]
+    expected: FAIL
+
+  [Text in CDATASection is considered when determining auto directionality]
+    expected: FAIL
+
+  [Directionality is updated when removing CDATASection]
+    expected: FAIL
+
+  [Directionality is updated when changing text of CDATASection]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/dom/elements/global-attributes/dir-assorted.window.js.ini b/tests/wpt/meta-legacy-layout/html/dom/elements/global-attributes/dir-assorted.window.js.ini
index 0daeceb99a1..1e6939b0478 100644
--- a/tests/wpt/meta-legacy-layout/html/dom/elements/global-attributes/dir-assorted.window.js.ini
+++ b/tests/wpt/meta-legacy-layout/html/dom/elements/global-attributes/dir-assorted.window.js.ini
@@ -118,3 +118,6 @@
 
   [non-html textarea element text contents influence dir=auto]
     expected: FAIL
+
+  [text changes apply to dir=auto on further ancestor after removing dir=ltr from closer ancestor]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/dom/elements/global-attributes/dir-auto-dynamic-changes.window.js.ini b/tests/wpt/meta-legacy-layout/html/dom/elements/global-attributes/dir-auto-dynamic-changes.window.js.ini
index 8becf694cfa..7395ce6f2ed 100644
--- a/tests/wpt/meta-legacy-layout/html/dom/elements/global-attributes/dir-auto-dynamic-changes.window.js.ini
+++ b/tests/wpt/meta-legacy-layout/html/dom/elements/global-attributes/dir-auto-dynamic-changes.window.js.ini
@@ -22,3 +22,27 @@
 
   [slotted non-HTML elements after dynamically assigning dir=auto, and dir attribute ignored on non-HTML elements]
     expected: FAIL
+
+  [dir=auto ancestor considers text in subtree after removing dir=ltr from it]
+    expected: FAIL
+
+  [Slotted content affects multiple dir=auto slots]
+    expected: FAIL
+
+  [Removing slotted content resets direction on dir=auto slot]
+    expected: FAIL
+
+  [Removing child of slotted content changes direction on dir=auto slot]
+    expected: FAIL
+
+  [Child directionality gets updated when dir=auto is set on parent]
+    expected: FAIL
+
+  [dir=auto slot is updated by text in value of input element children]
+    expected: FAIL
+
+  [dir=auto slot is updated if input stops being auto-directionality form-associated]
+    expected: FAIL
+
+  [slot provides updated directionality from host to a dir=auto container]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/dom/elements/global-attributes/dir-slots-directionality.html.ini b/tests/wpt/meta-legacy-layout/html/dom/elements/global-attributes/dir-slots-directionality.html.ini
index 2ff8bf31e7e..cd0a57e465c 100644
--- a/tests/wpt/meta-legacy-layout/html/dom/elements/global-attributes/dir-slots-directionality.html.ini
+++ b/tests/wpt/meta-legacy-layout/html/dom/elements/global-attributes/dir-slots-directionality.html.ini
@@ -25,3 +25,12 @@
 
   [slot with dir attribute is skipped by dir=auto]
     expected: FAIL
+
+  [dir=auto slot ignores dir attribute of assigned nodes]
+    expected: FAIL
+
+  [dir=auto slot considers text in bdi assigned nodes]
+    expected: FAIL
+
+  [dir=auto slot considers text in value of input element children]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/dom/idlharness.https.html.ini b/tests/wpt/meta-legacy-layout/html/dom/idlharness.https.html.ini
index 6cff25386a5..cdbd11bee52 100644
--- a/tests/wpt/meta-legacy-layout/html/dom/idlharness.https.html.ini
+++ b/tests/wpt/meta-legacy-layout/html/dom/idlharness.https.html.ini
@@ -1580,36 +1580,6 @@
   [SVGElement interface: attribute onbeforetoggle]
     expected: FAIL
 
-  [VisibilityStateEntry interface: existence and properties of interface object]
-    expected: FAIL
-
-  [VisibilityStateEntry interface object length]
-    expected: FAIL
-
-  [VisibilityStateEntry interface object name]
-    expected: FAIL
-
-  [VisibilityStateEntry interface: existence and properties of interface prototype object]
-    expected: FAIL
-
-  [VisibilityStateEntry interface: existence and properties of interface prototype object's "constructor" property]
-    expected: FAIL
-
-  [VisibilityStateEntry interface: existence and properties of interface prototype object's @@unscopables property]
-    expected: FAIL
-
-  [VisibilityStateEntry interface: attribute name]
-    expected: FAIL
-
-  [VisibilityStateEntry interface: attribute entryType]
-    expected: FAIL
-
-  [VisibilityStateEntry interface: attribute startTime]
-    expected: FAIL
-
-  [VisibilityStateEntry interface: attribute duration]
-    expected: FAIL
-
   [Navigation interface: existence and properties of interface object]
     expected: FAIL
 
@@ -2608,12 +2578,6 @@
   [Window interface: calling structuredClone(any, optional StructuredSerializeOptions) on window with too few arguments must throw TypeError]
     expected: FAIL
 
-  [Document interface: attribute hidden]
-    expected: FAIL
-
-  [Document interface: attribute visibilityState]
-    expected: FAIL
-
   [Document interface: attribute onvisibilitychange]
     expected: FAIL
 
@@ -2623,12 +2587,6 @@
   [Document interface: attribute oncontextrestored]
     expected: FAIL
 
-  [Document interface: iframe.contentDocument must inherit property "hidden" with the proper type]
-    expected: FAIL
-
-  [Document interface: iframe.contentDocument must inherit property "visibilityState" with the proper type]
-    expected: FAIL
-
   [Document interface: iframe.contentDocument must inherit property "onvisibilitychange" with the proper type]
     expected: FAIL
 
@@ -2638,12 +2596,6 @@
   [Document interface: iframe.contentDocument must inherit property "oncontextrestored" with the proper type]
     expected: FAIL
 
-  [Document interface: new Document() must inherit property "hidden" with the proper type]
-    expected: FAIL
-
-  [Document interface: new Document() must inherit property "visibilityState" with the proper type]
-    expected: FAIL
-
   [Document interface: new Document() must inherit property "onvisibilitychange" with the proper type]
     expected: FAIL
 
@@ -2653,12 +2605,6 @@
   [Document interface: new Document() must inherit property "oncontextrestored" with the proper type]
     expected: FAIL
 
-  [Document interface: documentWithHandlers must inherit property "hidden" with the proper type]
-    expected: FAIL
-
-  [Document interface: documentWithHandlers must inherit property "visibilityState" with the proper type]
-    expected: FAIL
-
   [Document interface: documentWithHandlers must inherit property "onvisibilitychange" with the proper type]
     expected: FAIL
 
diff --git a/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/media-elements/audio_loop_base.html.ini b/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/media-elements/audio_loop_base.html.ini
deleted file mode 100644
index c6977a66f6d..00000000000
--- a/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/media-elements/audio_loop_base.html.ini
+++ /dev/null
@@ -1,5 +0,0 @@
-[audio_loop_base.html]
-  expected: TIMEOUT
-  [Check if audio.loop is set to true that expecting the seeking event is fired more than once]
-    expected: NOTRUN
-
diff --git a/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/media-elements/audio_loop_seek_to_eos.html.ini b/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/media-elements/audio_loop_seek_to_eos.html.ini
deleted file mode 100644
index 235627d1539..00000000000
--- a/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/media-elements/audio_loop_seek_to_eos.html.ini
+++ /dev/null
@@ -1,3 +0,0 @@
-[audio_loop_seek_to_eos.html]
-  [seeking to the end of looping audio]
-    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/media-elements/playing-the-media-resource/loop-from-ended.tentative.html.ini b/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/media-elements/playing-the-media-resource/loop-from-ended.tentative.html.ini
index 6d9188c1e52..6897533d946 100644
--- a/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/media-elements/playing-the-media-resource/loop-from-ended.tentative.html.ini
+++ b/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/media-elements/playing-the-media-resource/loop-from-ended.tentative.html.ini
@@ -1,7 +1,7 @@
 [loop-from-ended.tentative.html]
+  expected: TIMEOUT
   [Test looping edge case to verify http://crbug.com/364442.]
     expected: FAIL
 
   [play() with loop set to true after playback ended]
-    expected: FAIL
-
+    expected: TIMEOUT
diff --git a/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/media-elements/track/track-element/no-cuechange-before-play.html.ini b/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/media-elements/track/track-element/no-cuechange-before-play.html.ini
index 4caf5931a11..246e55deb7e 100644
--- a/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/media-elements/track/track-element/no-cuechange-before-play.html.ini
+++ b/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/media-elements/track/track-element/no-cuechange-before-play.html.ini
@@ -1,3 +1,4 @@
 [no-cuechange-before-play.html]
+  expected: TIMEOUT
   [Ensure that the 'cuechange' event is not fired before video playback has begun.]
-    expected: FAIL
+    expected: TIMEOUT
diff --git a/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/media-elements/track/track-element/track-cue-mutable-fragment.html.ini b/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/media-elements/track/track-element/track-cue-mutable-fragment.html.ini
index c1216306fcf..4044b3cd259 100644
--- a/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/media-elements/track/track-element/track-cue-mutable-fragment.html.ini
+++ b/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/media-elements/track/track-element/track-cue-mutable-fragment.html.ini
@@ -1,4 +1,4 @@
 [track-cue-mutable-fragment.html]
+  expected: TIMEOUT
   [Cue fragment is mutable]
-    expected: FAIL
-
+    expected: TIMEOUT
diff --git a/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/media-elements/track/track-element/track-mode-not-changed-by-new-track.html.ini b/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/media-elements/track/track-element/track-mode-not-changed-by-new-track.html.ini
index d0fc025a457..305b9bd7896 100644
--- a/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/media-elements/track/track-element/track-mode-not-changed-by-new-track.html.ini
+++ b/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/media-elements/track/track-element/track-mode-not-changed-by-new-track.html.ini
@@ -1,4 +1,4 @@
 [track-mode-not-changed-by-new-track.html]
+  expected: TIMEOUT
   [A track appended after the initial track configuration does not change other tracks]
-    expected: FAIL
-
+    expected: TIMEOUT
diff --git a/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/the-iframe-element/iframe-loading-lazy-nav-form-submit.html.ini b/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/the-iframe-element/iframe-loading-lazy-nav-form-submit.html.ini
new file mode 100644
index 00000000000..721952ed48a
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/the-iframe-element/iframe-loading-lazy-nav-form-submit.html.ini
@@ -0,0 +1,3 @@
+[iframe-loading-lazy-nav-form-submit.html]
+  [Navigating iframe loading='lazy' before it is loaded: form submit]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/the-iframe-element/iframe-loading-lazy-nav-location-assign.html.ini b/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/the-iframe-element/iframe-loading-lazy-nav-location-assign.html.ini
deleted file mode 100644
index 68a30137729..00000000000
--- a/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/the-iframe-element/iframe-loading-lazy-nav-location-assign.html.ini
+++ /dev/null
@@ -1,3 +0,0 @@
-[iframe-loading-lazy-nav-location-assign.html]
-  [Navigating iframe loading='lazy' before it is loaded: location.assign]
-    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-3.html.ini b/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-3.html.ini
index eacbe5794ea..fe55ddae3f1 100644
--- a/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-3.html.ini
+++ b/tests/wpt/meta-legacy-layout/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-3.html.ini
@@ -1,5 +1,4 @@
 [iframe_sandbox_popups_escaping-3.html]
   type: testharness
-  expected: TIMEOUT
   [Check that popups from a sandboxed iframe escape the sandbox if\n       allow-popups-to-escape-sandbox is used]
-    expected: TIMEOUT
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/semantics/invokers/idlharness.tentative.html.ini b/tests/wpt/meta-legacy-layout/html/semantics/invokers/idlharness.tentative.html.ini
index f9d4b78a7c6..cd96793eab1 100644
--- a/tests/wpt/meta-legacy-layout/html/semantics/invokers/idlharness.tentative.html.ini
+++ b/tests/wpt/meta-legacy-layout/html/semantics/invokers/idlharness.tentative.html.ini
@@ -34,3 +34,39 @@
 
   [InvokeEvent interface: new InvokeEvent("invoke") must inherit property "action" with the proper type]
     expected: FAIL
+
+  [CommandEvent interface: existence and properties of interface object]
+    expected: FAIL
+
+  [CommandEvent interface object length]
+    expected: FAIL
+
+  [CommandEvent interface object name]
+    expected: FAIL
+
+  [CommandEvent interface: existence and properties of interface prototype object]
+    expected: FAIL
+
+  [CommandEvent interface: existence and properties of interface prototype object's "constructor" property]
+    expected: FAIL
+
+  [CommandEvent interface: existence and properties of interface prototype object's @@unscopables property]
+    expected: FAIL
+
+  [CommandEvent interface: attribute invoker]
+    expected: FAIL
+
+  [CommandEvent interface: attribute command]
+    expected: FAIL
+
+  [CommandEvent must be primary interface of new CommandEvent("invoke")]
+    expected: FAIL
+
+  [Stringification of new CommandEvent("invoke")]
+    expected: FAIL
+
+  [CommandEvent interface: new CommandEvent("invoke") must inherit property "invoker" with the proper type]
+    expected: FAIL
+
+  [CommandEvent interface: new CommandEvent("invoke") must inherit property "command" with the proper type]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/html/semantics/invokers/invokeelement-interface.tentative.html.ini b/tests/wpt/meta-legacy-layout/html/semantics/invokers/invokeelement-interface.tentative.html.ini
index 587bdaf84d3..d04574db48e 100644
--- a/tests/wpt/meta-legacy-layout/html/semantics/invokers/invokeelement-interface.tentative.html.ini
+++ b/tests/wpt/meta-legacy-layout/html/semantics/invokers/invokeelement-interface.tentative.html.ini
@@ -43,3 +43,33 @@
 
   [invokeAction reflects '' when attribute set to [\]]
     expected: FAIL
+
+  [commandForElement reflects invokee HTML element]
+    expected: FAIL
+
+  [commandForElement reflects set value]
+    expected: FAIL
+
+  [commandForElement reflects set value across shadow root into light dom]
+    expected: FAIL
+
+  [commandForElement does not reflect set value inside shadowroot]
+    expected: FAIL
+
+  [commandForElement throws error on assignment of non Element]
+    expected: FAIL
+
+  [command reflects '' when attribute empty, setAttribute version]
+    expected: FAIL
+
+  [command reflects same casing]
+    expected: FAIL
+
+  [command reflects tostring value]
+    expected: FAIL
+
+  [command reflects '' when attribute set to [\]]
+    expected: FAIL
+
+  [command reflects tostring value 2]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/page-visibility/iframe-session-history.html.ini b/tests/wpt/meta-legacy-layout/page-visibility/iframe-session-history.html.ini
new file mode 100644
index 00000000000..64437c7c804
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/page-visibility/iframe-session-history.html.ini
@@ -0,0 +1,3 @@
+[iframe-session-history.html]
+  [pagehide should be called before visibilitychange, and visibilityState should be set to hidden at the right time]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/page-visibility/iframe-unload.html.ini b/tests/wpt/meta-legacy-layout/page-visibility/iframe-unload.html.ini
new file mode 100644
index 00000000000..4df96d83d37
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/page-visibility/iframe-unload.html.ini
@@ -0,0 +1,4 @@
+[iframe-unload.html]
+  expected: TIMEOUT
+  [visibilitychange fires on unload with iframes]
+    expected: TIMEOUT
diff --git a/tests/wpt/meta-legacy-layout/page-visibility/onvisibilitychange.html.ini b/tests/wpt/meta-legacy-layout/page-visibility/onvisibilitychange.html.ini
new file mode 100644
index 00000000000..4998c11da7b
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/page-visibility/onvisibilitychange.html.ini
@@ -0,0 +1,4 @@
+[onvisibilitychange.html]
+  expected: TIMEOUT
+  [onvisibilitychange attribute is a proper event handler]
+    expected: NOTRUN
diff --git a/tests/wpt/meta-legacy-layout/page-visibility/test_child_document.html.ini b/tests/wpt/meta-legacy-layout/page-visibility/test_child_document.html.ini
new file mode 100644
index 00000000000..9e77ac067f4
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/page-visibility/test_child_document.html.ini
@@ -0,0 +1,9 @@
+[test_child_document.html]
+  [document.visibilityState for frame with no style attribute == visible]
+    expected: FAIL
+
+  [document.visibilityState for frame with 'display:none' style == visible]
+    expected: FAIL
+
+  [document.visibilityState for frame with 'visibility:hidden' style == visible]
+    expected: FAIL
diff --git a/tests/wpt/meta-legacy-layout/page-visibility/unload-bubbles.html.ini b/tests/wpt/meta-legacy-layout/page-visibility/unload-bubbles.html.ini
new file mode 100644
index 00000000000..c4af1f5f836
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/page-visibility/unload-bubbles.html.ini
@@ -0,0 +1,4 @@
+[unload-bubbles.html]
+  expected: TIMEOUT
+  [visibilitychange event bubbles when fired on unload]
+    expected: TIMEOUT
diff --git a/tests/wpt/meta-legacy-layout/page-visibility/unload.html.ini b/tests/wpt/meta-legacy-layout/page-visibility/unload.html.ini
new file mode 100644
index 00000000000..6e9a94351a0
--- /dev/null
+++ b/tests/wpt/meta-legacy-layout/page-visibility/unload.html.ini
@@ -0,0 +1,4 @@
+[unload.html]
+  expected: TIMEOUT
+  [visibilitychange fires on unload]
+    expected: TIMEOUT
diff --git a/tests/wpt/meta-legacy-layout/resource-timing/test_resource_timing.https.html.ini b/tests/wpt/meta-legacy-layout/resource-timing/test_resource_timing.https.html.ini
index 32d149c8ae9..54e3ef35665 100644
--- a/tests/wpt/meta-legacy-layout/resource-timing/test_resource_timing.https.html.ini
+++ b/tests/wpt/meta-legacy-layout/resource-timing/test_resource_timing.https.html.ini
@@ -68,6 +68,3 @@
 
   [PerformanceEntry has correct name, initiatorType, startTime, and duration (link)]
     expected: NOTRUN
-
-  [PerformanceEntry has correct name, initiatorType, startTime, and duration (img)]
-    expected: FAIL
diff --git a/tests/wpt/meta/MANIFEST.json b/tests/wpt/meta/MANIFEST.json
index 9cc453d7319..19cdffd47c9 100644
--- a/tests/wpt/meta/MANIFEST.json
+++ b/tests/wpt/meta/MANIFEST.json
@@ -482,6 +482,13 @@
          {}
         ]
        ],
+       "firefox-bug-1906768.html": [
+        "0300a90b206f2149414d5b00c31c1a45eacc15bc",
+        [
+         null,
+         {}
+        ]
+       ],
        "float-rewind-parallel-flow-1-crash.html": [
         "79d90b89b6523ccb64502d1b43b6b0a054148cd1",
         [
@@ -5549,6 +5556,13 @@
          null,
          {}
         ]
+       ],
+       "input-moveBefore-crash.html": [
+        "a41d06b024ebce951d9b84c9759a29b5754d0e96",
+        [
+         null,
+         {}
+        ]
        ]
       }
      },
@@ -6737,6 +6751,15 @@
         {}
        ]
       ]
+     },
+     "widgets": {
+      "input-checkbox-appearance-none-dynamic-crash.html": [
+       "fb10f6a7fa63a62eee988778b902179ab38e3603",
+       [
+        null,
+        {}
+       ]
+      ]
      }
     },
     "semantics": {
@@ -32072,6 +32095,23 @@
       ]
      ]
     },
+    "css-contain": {
+     "content-visibility": {
+      "content-visibility-auto-print.html": [
+       "35bc333e87976b47971a303db1eb306ffdac5674",
+       [
+        null,
+        [
+         [
+          "/css/css-contain/content-visibility/content-visibility-auto-print-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ]
+     }
+    },
     "css-flexbox": {
      "break-nested-float-in-flex-item-001-print.html": [
       "2fbf939f6a54c9056b4bd39fe0466f0df25f0bb0",
@@ -33201,6 +33241,45 @@
        {}
       ]
      ],
+     "page-background-001-print.html": [
+      "e1bc2196940047d8948f819c32d65aedd0e76416",
+      [
+       null,
+       [
+        [
+         "/css/css-page/page-background-001-print-ref.html",
+         "=="
+        ]
+       ],
+       {}
+      ]
+     ],
+     "page-background-002-print.html": [
+      "240d468ce4438ee29a6afb74aee1539b897b5ea5",
+      [
+       null,
+       [
+        [
+         "/css/css-page/page-background-002-print-ref.html",
+         "=="
+        ]
+       ],
+       {}
+      ]
+     ],
+     "page-background-003-print.html": [
+      "fbc72ecd7d77bd0a2382149019495736e7be34ce",
+      [
+       null,
+       [
+        [
+         "/css/css-page/page-background-003-print-ref.html",
+         "=="
+        ]
+       ],
+       {}
+      ]
+     ],
      "page-background-image-print.html": [
       "633cd4ec6c9027902782f271c2161394cf6cb5e6",
       [
@@ -134634,6 +134713,71 @@
        {}
       ]
      ],
+     "box-decoration-break-clone-005.tentative.html": [
+      "88ca6360f101d88e9d91c145ae2757539ca9e5aa",
+      [
+       null,
+       [
+        [
+         "/css/reference/ref-filled-green-100px-square.xht",
+         "=="
+        ]
+       ],
+       {}
+      ]
+     ],
+     "box-decoration-break-clone-006.html": [
+      "657f9f8442dcea268927b20ea0e9b4853912968f",
+      [
+       null,
+       [
+        [
+         "/css/reference/ref-filled-green-100px-square.xht",
+         "=="
+        ]
+       ],
+       {}
+      ]
+     ],
+     "box-decoration-break-clone-007.html": [
+      "f2855edaff8d729c1aa30f3e2bf503c9fc10c262",
+      [
+       null,
+       [
+        [
+         "/css/reference/ref-filled-green-100px-square.xht",
+         "=="
+        ]
+       ],
+       {}
+      ]
+     ],
+     "box-decoration-break-clone-008.html": [
+      "5f13231883515ef1e1f33906e9243c18d5b14c06",
+      [
+       null,
+       [
+        [
+         "/css/reference/ref-filled-green-100px-square.xht",
+         "=="
+        ]
+       ],
+       {}
+      ]
+     ],
+     "box-decoration-break-clone-009.html": [
+      "1db904332aef57c46d406881ec70adbcf4a6a0ec",
+      [
+       null,
+       [
+        [
+         "/css/css-break/box-decoration-break-clone-009-ref.html",
+         "=="
+        ]
+       ],
+       {}
+      ]
+     ],
      "box-shadow-001.html": [
       "d35aeb682dcfcc77c41f8b09642b3481a4b7f39d",
       [
@@ -146084,7 +146228,7 @@
       ]
      ],
      "color-mix-non-srgb-001.html": [
-      "7563581a4cf6f8438e1ad9a8a25671c3f052ce79",
+      "550a919d241f805a24704015f3b50ac8a84064f3",
       [
        null,
        [
@@ -156458,6 +156602,19 @@
         {}
        ]
       ],
+      "content-visibility-auto-svg-image.html": [
+       "46de764072df987da7ba52e1790e9334af68bd20",
+       [
+        null,
+        [
+         [
+          "/css/css-contain/content-visibility/content-visibility-auto-svg-image-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
       "content-visibility-canvas.html": [
        "fe469489528c45797b8ff68bfc739c39cefdf7b0",
        [
@@ -201518,6 +201675,19 @@
      },
      "clip-path": {
       "animations": {
+       "clip-path-animation-cancel.html": [
+        "f92a016662b4e0885f8db76575e07081689b29d6",
+        [
+         null,
+         [
+          [
+           "/css/css-masking/clip-path/animations/clip-path-animation-cancel-ref.html",
+           "=="
+          ]
+         ],
+         {}
+        ]
+       ],
        "clip-path-animation-custom-timing-function-reverse.html": [
         "5346a4c22421cafde7691356c67b896f22392f76",
         [
@@ -214244,6 +214414,84 @@
         {}
        ]
       ],
+      "line-clamp-022.tentative.html": [
+       "1ae5d94465aac2ebca3a30f749302610e2c175ed",
+       [
+        null,
+        [
+         [
+          "/css/css-overflow/line-clamp/reference/line-clamp-022-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "line-clamp-023.tentative.html": [
+       "0e11ba4d8625bc5693cc114202479fbe99fa9e39",
+       [
+        null,
+        [
+         [
+          "/css/css-overflow/line-clamp/reference/line-clamp-023-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "line-clamp-024.tentative.html": [
+       "0efb474a11fb7d48dc05439e448dee9e51c5c260",
+       [
+        null,
+        [
+         [
+          "/css/css-overflow/line-clamp/reference/line-clamp-022-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "line-clamp-025.tentative.html": [
+       "b2a2c54f450bee13863bfce292164c48a705a7d4",
+       [
+        null,
+        [
+         [
+          "/css/css-overflow/line-clamp/reference/line-clamp-023-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "line-clamp-026.tentative.html": [
+       "329d12d10bd1021a6565b09be013aeefea973fc6",
+       [
+        null,
+        [
+         [
+          "/css/css-overflow/line-clamp/reference/line-clamp-026-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "line-clamp-027.tentative.html": [
+       "b2a376b2bd93c577e426d5d6f7a52ccf016b0b75",
+       [
+        null,
+        [
+         [
+          "/css/css-overflow/line-clamp/reference/line-clamp-027-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
       "line-clamp-auto-001.tentative.html": [
        "02d8479736d4d6fd7e26df53611624e7a75d0989",
        [
@@ -214452,6 +214700,214 @@
         {}
        ]
       ],
+      "line-clamp-auto-017.tentative.html": [
+       "376c69a210611977b3eae9ed3900b2538516be98",
+       [
+        null,
+        [
+         [
+          "/css/css-overflow/line-clamp/reference/webkit-line-clamp-005-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "line-clamp-auto-018.tentative.html": [
+       "deb1f42431d26c503d5abd6f22ba567d2ecd446f",
+       [
+        null,
+        [
+         [
+          "/css/css-overflow/line-clamp/reference/line-clamp-auto-018-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "line-clamp-auto-019.tentative.html": [
+       "82c53dc6bbec03a810dc04538a5bc714cd5802fd",
+       [
+        null,
+        [
+         [
+          "/css/css-overflow/line-clamp/reference/line-clamp-auto-019-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "line-clamp-auto-020.tentative.html": [
+       "eb84151ca66c1a42b8ff35690946350450fcec46",
+       [
+        null,
+        [
+         [
+          "/css/css-overflow/line-clamp/reference/line-clamp-auto-020-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "line-clamp-auto-021.tentative.html": [
+       "90c33755bee669e770cf2a9a699998ea67c19fc6",
+       [
+        null,
+        [
+         [
+          "/css/css-overflow/line-clamp/reference/line-clamp-auto-021-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "line-clamp-auto-022.tentative.html": [
+       "7834c9c3ae0e2d2120f5fbc47f7946908235dedd",
+       [
+        null,
+        [
+         [
+          "/css/css-overflow/line-clamp/reference/line-clamp-auto-021-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "line-clamp-auto-023.tentative.html": [
+       "d41d68d84a3f9518a64aae73bb6d8f990d9ee160",
+       [
+        null,
+        [
+         [
+          "/css/css-overflow/line-clamp/reference/line-clamp-auto-023-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "line-clamp-auto-024.tentative.html": [
+       "134dade711ad9ff4dcb3cb310e23a5a5e5e492ea",
+       [
+        null,
+        [
+         [
+          "/css/css-overflow/line-clamp/reference/line-clamp-auto-023-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "line-clamp-auto-025.tentative.html": [
+       "ee394b2a76d12a276c8809577e92993e2e32e7a8",
+       [
+        null,
+        [
+         [
+          "/css/css-overflow/line-clamp/reference/line-clamp-auto-025-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "line-clamp-auto-026.tentative.html": [
+       "f616cbed028a82638dfd84465e134230eb109219",
+       [
+        null,
+        [
+         [
+          "/css/css-overflow/line-clamp/reference/line-clamp-auto-026-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "line-clamp-auto-027.tentative.html": [
+       "9ed461d8cfb4c2ee035987148e15b6dcce3cdffa",
+       [
+        null,
+        [
+         [
+          "/css/css-overflow/line-clamp/reference/line-clamp-auto-027-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "line-clamp-auto-028.tentative.html": [
+       "e3bcf375bc55fa0d51b36af41a716188be52e8b1",
+       [
+        null,
+        [
+         [
+          "/css/css-overflow/line-clamp/reference/line-clamp-auto-028-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "line-clamp-auto-029.tentative.html": [
+       "17a3f1a78c1aa045cb71d37a267c69f312b8e5f8",
+       [
+        null,
+        [
+         [
+          "/css/css-overflow/line-clamp/reference/line-clamp-auto-029-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "line-clamp-auto-030.tentative.html": [
+       "2a3a73b3e7121b80a4954bcb623e05a988ea43e2",
+       [
+        null,
+        [
+         [
+          "/css/css-overflow/line-clamp/reference/line-clamp-auto-029-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
+      "line-clamp-auto-031.tentative.html": [
+       "a723430c83ed7f0ea8ae8f2966d971c5c56d3cff",
+       [
+        null,
+        [
+         [
+          "/css/css-overflow/line-clamp/reference/line-clamp-auto-031-ref.html",
+          "=="
+         ]
+        ],
+        {}
+       ]
+      ],
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     "payment-allowed-by-permissions-policy-attribute-redirect-on-load.https.sub.html": [
-     "b95deed7cef5ae9a82286543e6c1911c7bdaea4f",
+     "57ae4fbee45f99803ac186cd04c5e07f48ecc8fe",
      [
       null,
       {}
@@ -723254,7 +724023,7 @@
      ]
     ],
     "sanitizer-names.https.html": [
-     "cd33bbc7635322c9933186662da1ace396ad325c",
+     "78f1d605a19e02fac1e760f582d80a57e7ddb0db",
      [
       null,
       {}
@@ -727169,7 +727938,7 @@
      ]
     ],
     "onselectionchange-on-document.html": [
-     "4e0616537771ef3763f9c1b4950964d81cb1b9f5",
+     "af522c3f79c96b53547ee9001b700c45a444119d",
      [
       null,
       {}
@@ -731953,7 +732722,7 @@
      ]
     ],
     "selection-direction.tentative.html": [
-     "6ec9b1934f989e289aa6b746b605456fa1929d11",
+     "340711a8f0682d2736fa355efadab337189a6feb",
      [
       null,
       {
@@ -737951,10 +738720,10 @@
       {}
      ]
     ],
-    "storage-access-beyond-cookies.BroadcastChannel.tentative.sub.https.window.js": [
+    "storage-access-beyond-cookies.BroadcastChannel.sub.https.window.js": [
      "feb268b4b8146290eec743779c4a8d9567bc74b3",
      [
-      "storage-access-api/storage-access-beyond-cookies.BroadcastChannel.tentative.sub.https.window.html",
+      "storage-access-api/storage-access-beyond-cookies.BroadcastChannel.sub.https.window.html",
       {
        "script_metadata": [
         [
@@ -737969,10 +738738,10 @@
       }
      ]
     ],
-    "storage-access-beyond-cookies.SharedWorker.tentative.sub.https.window.js": [
-     "613a47ba1b7c5cdcfa7db7531e921ad72a9a8501",
+    "storage-access-beyond-cookies.SharedWorker.sub.https.window.js": [
+     "e05c2ef38d171db26628317018312d3f2f46d7d2",
      [
-      "storage-access-api/storage-access-beyond-cookies.SharedWorker.tentative.sub.https.window.html",
+      "storage-access-api/storage-access-beyond-cookies.SharedWorker.sub.https.window.html",
       {
        "script_metadata": [
         [
@@ -737987,10 +738756,10 @@
       }
      ]
     ],
-    "storage-access-beyond-cookies.blobStorage.tentative.sub.https.window.js": [
+    "storage-access-beyond-cookies.blobStorage.sub.https.window.js": [
      "cc2785b6fac73ffbd3a18c8bd23228a1c8130e9c",
      [
-      "storage-access-api/storage-access-beyond-cookies.blobStorage.tentative.sub.https.window.html",
+      "storage-access-api/storage-access-beyond-cookies.blobStorage.sub.https.window.html",
       {
        "script_metadata": [
         [
@@ -738005,10 +738774,10 @@
       }
      ]
     ],
-    "storage-access-beyond-cookies.caches.tentative.sub.https.window.js": [
+    "storage-access-beyond-cookies.caches.sub.https.window.js": [
      "51e5c648a64cd9f7e629c1d5fe9d8c471d6513d9",
      [
-      "storage-access-api/storage-access-beyond-cookies.caches.tentative.sub.https.window.html",
+      "storage-access-api/storage-access-beyond-cookies.caches.sub.https.window.html",
       {
        "script_metadata": [
         [
@@ -738023,10 +738792,10 @@
       }
      ]
     ],
-    "storage-access-beyond-cookies.cookies.tentative.sub.https.window.js": [
+    "storage-access-beyond-cookies.cookies.sub.https.window.js": [
      "ad760cfda7d8e442da3df71db0154627fdbe4b02",
      [
-      "storage-access-api/storage-access-beyond-cookies.cookies.tentative.sub.https.window.html",
+      "storage-access-api/storage-access-beyond-cookies.cookies.sub.https.window.html",
       {
        "script_metadata": [
         [
@@ -738041,10 +738810,10 @@
       }
      ]
     ],
-    "storage-access-beyond-cookies.estimate.tentative.sub.https.window.js": [
+    "storage-access-beyond-cookies.estimate.sub.https.window.js": [
      "eb8cb0c68d0ad83e526198545fd1bb31070366b3",
      [
-      "storage-access-api/storage-access-beyond-cookies.estimate.tentative.sub.https.window.html",
+      "storage-access-api/storage-access-beyond-cookies.estimate.sub.https.window.html",
       {
        "script_metadata": [
         [
@@ -738059,10 +738828,10 @@
       }
      ]
     ],
-    "storage-access-beyond-cookies.getDirectory.tentative.sub.https.window.js": [
+    "storage-access-beyond-cookies.getDirectory.sub.https.window.js": [
      "d59caa93cd63b3edc8f107ed1fa9ba766db3d287",
      [
-      "storage-access-api/storage-access-beyond-cookies.getDirectory.tentative.sub.https.window.html",
+      "storage-access-api/storage-access-beyond-cookies.getDirectory.sub.https.window.html",
       {
        "script_metadata": [
         [
@@ -738077,10 +738846,10 @@
       }
      ]
     ],
-    "storage-access-beyond-cookies.indexedDB.tentative.sub.https.window.js": [
+    "storage-access-beyond-cookies.indexedDB.sub.https.window.js": [
      "8e9420da0da652f4bade46c9deedd66af8decf3c",
      [
-      "storage-access-api/storage-access-beyond-cookies.indexedDB.tentative.sub.https.window.html",
+      "storage-access-api/storage-access-beyond-cookies.indexedDB.sub.https.window.html",
       {
        "script_metadata": [
         [
@@ -738095,10 +738864,10 @@
       }
      ]
     ],
-    "storage-access-beyond-cookies.localStorage.tentative.sub.https.window.js": [
+    "storage-access-beyond-cookies.localStorage.sub.https.window.js": [
      "80021317790587e8da7fea06324cc03a1504a8ce",
      [
-      "storage-access-api/storage-access-beyond-cookies.localStorage.tentative.sub.https.window.html",
+      "storage-access-api/storage-access-beyond-cookies.localStorage.sub.https.window.html",
       {
        "script_metadata": [
         [
@@ -738113,10 +738882,10 @@
       }
      ]
     ],
-    "storage-access-beyond-cookies.locks.tentative.sub.https.window.js": [
+    "storage-access-beyond-cookies.locks.sub.https.window.js": [
      "ed7d6ea48479a1b2a433db5f438ab001bae93598",
      [
-      "storage-access-api/storage-access-beyond-cookies.locks.tentative.sub.https.window.html",
+      "storage-access-api/storage-access-beyond-cookies.locks.sub.https.window.html",
       {
        "script_metadata": [
         [
@@ -738131,10 +738900,10 @@
       }
      ]
     ],
-    "storage-access-beyond-cookies.none.tentative.sub.https.window.js": [
+    "storage-access-beyond-cookies.none.sub.https.window.js": [
      "ba5ea3279dffe0253f29293536ce2b408a4fe72a",
      [
-      "storage-access-api/storage-access-beyond-cookies.none.tentative.sub.https.window.html",
+      "storage-access-api/storage-access-beyond-cookies.none.sub.https.window.html",
       {
        "script_metadata": [
         [
@@ -738149,10 +738918,10 @@
       }
      ]
     ],
-    "storage-access-beyond-cookies.sessionStorage.tentative.sub.https.window.js": [
+    "storage-access-beyond-cookies.sessionStorage.sub.https.window.js": [
      "93b243f6c1104401f05aff207acdf16186b97899",
      [
-      "storage-access-api/storage-access-beyond-cookies.sessionStorage.tentative.sub.https.window.html",
+      "storage-access-api/storage-access-beyond-cookies.sessionStorage.sub.https.window.html",
       {
        "script_metadata": [
         [
@@ -738167,10 +738936,10 @@
       }
      ]
     ],
-    "storage-access-beyond-cookies.unpartitioned.tentative.sub.https.window.js": [
+    "storage-access-beyond-cookies.unpartitioned.sub.https.window.js": [
      "ddc5b49f4819fc127a99d30ebc2792244cae3570",
      [
-      "storage-access-api/storage-access-beyond-cookies.unpartitioned.tentative.sub.https.window.html",
+      "storage-access-api/storage-access-beyond-cookies.unpartitioned.sub.https.window.html",
       {
        "script_metadata": [
         [
@@ -746849,14 +747618,7 @@
       ]
      ],
      "vector-effect-invalid.html": [
-      "ec49b88c59959ce33b6b3914026b25003cf74ee8",
-      [
-       null,
-       {}
-      ]
-     ],
-     "vector-effect-valid.html": [
-      "9563db0523ba741a94887c9e98d1db37b6da327b",
+      "18f82502ddd3369d477fba0a7b5f96b3c77150ff",
       [
        null,
        {}
@@ -763161,7 +763923,7 @@
      ]
     ],
     "audio-encoder-config.https.any.js": [
-     "a70bf28f80c9ab576a569d9a9798d727133150d5",
+     "ad5d56ca492a6cdf4a0be8338c30647db9e616c6",
      [
       "webcodecs/audio-encoder-config.https.any.html",
       {
@@ -763844,7 +764606,7 @@
      ]
     ],
     "full-cycle-test.https.any.js": [
-     "8e1ae65bdcad6427cfc5901c9411ddca9568deb0",
+     "a63edd04d75ea1c3921456a7179ade7cf39a8375",
      [
       "webcodecs/full-cycle-test.https.any.html?av1",
       {
@@ -766465,7 +767227,7 @@
      ]
     ],
     "video-encoder-config.https.any.js": [
-     "8d554e4f4dbb935d12a6c7e3aa606fc50db01424",
+     "d61958919d78b9e246a7021fa9c19242cb6d7538",
      [
       "webcodecs/video-encoder-config.https.any.html",
       {
@@ -767850,7 +768612,7 @@
      ]
     ],
     "videoFrame-copyTo-rgb.any.js": [
-     "146b6756cb467335087dd234e63b4e9afcd03adb",
+     "eb7351e048b2aff4cff3f2df793ef4741fb1db8d",
      [
       "webcodecs/videoFrame-copyTo-rgb.any.html",
       {
@@ -781432,7 +782194,7 @@
       ]
      ],
      "convTranspose2d.https.any.js": [
-      "c4717a7c538779271f7f806d9b286c18dece87ea",
+      "f7cf4b3200ca280688eb4a244a75b620aebc5c4d",
       [
        "webnn/validation_tests/convTranspose2d.https.any.html",
        {
@@ -781801,7 +782563,7 @@
       ]
      ],
      "gru.https.any.js": [
-      "b1b576e96d070387e36f609f360122bd81f8e10a",
+      "2b85ce23144ca9c7bd7d65975cfb8c230d1cb071",
       [
        "webnn/validation_tests/gru.https.any.html",
        {
@@ -781842,7 +782604,7 @@
       ]
      ],
      "gruCell.https.any.js": [
-      "0465928d514fab705c710707fb89463d8ea100e1",
+      "e37c9ec5209912078b6238d0c544778740e02e83",
       [
        "webnn/validation_tests/gruCell.https.any.html",
        {
@@ -782170,7 +782932,7 @@
       ]
      ],
      "lstm.https.any.js": [
-      "2a3eaa1c20258b9e2e6177c34c651d41e11e21a5",
+      "06834b3960437d821fcdd5e35551ba6dd7608e4a",
       [
        "webnn/validation_tests/lstm.https.any.html",
        {
@@ -782211,7 +782973,7 @@
       ]
      ],
      "lstmCell.https.any.js": [
-      "d4031b07b24e61054828cd3ff84ceead68ad12bb",
+      "6b7bd1958b323980876269c28bfdfd96610ee8bd",
       [
        "webnn/validation_tests/lstmCell.https.any.html",
        {
@@ -782393,7 +783155,7 @@
       ]
      ],
      "pooling.https.any.js": [
-      "08a78f25bafe92803968a88ea07e174d3cafbd78",
+      "6d21f3d52f1c3402faf7b860ba960144fce53121",
       [
        "webnn/validation_tests/pooling.https.any.html",
        {
@@ -782557,7 +783319,7 @@
       ]
      ],
      "resample2d.https.any.js": [
-      "cc52cf97f4ff571cd9a6d7223fbece79a8c8cc3e",
+      "0c6a475e878486453722a2a9e7dcdac0bb177424",
       [
        "webnn/validation_tests/resample2d.https.any.html",
        {
@@ -782844,7 +783606,7 @@
       ]
      ],
      "split.https.any.js": [
-      "6f7809744a7b6ecdceda9a9b97e50176c5b1e884",
+      "91d00b0a6d71ff5e92ac1fac9c38586d665ebe39",
       [
        "webnn/validation_tests/split.https.any.html",
        {
@@ -783008,7 +783770,7 @@
       ]
      ],
      "where.https.any.js": [
-      "a26fa249315d3bdda9dbdc7e1c5e623135aa9c0b",
+      "33394f863227ccc906a16e3175285a237d68e023",
       [
        "webnn/validation_tests/where.https.any.html",
        {
@@ -830139,7 +830901,7 @@
          ]
         ],
         "prompt_unload.py": [
-         "2dc241ba396fd5988c6c95f36afedcab950077b6",
+         "e7d88ad272d0ae0a3cabef1bfb2b675475e70698",
          [
           null,
           {}
@@ -830279,7 +831041,7 @@
        },
        "handle_user_prompt": {
         "handle_user_prompt.py": [
-         "5bbc616960fa0461e9cf14ceca918217f633b381",
+         "9044f220bcc8d242a15b415a76882f102ee9d9dc",
          [
           null,
           {}
@@ -830569,7 +831331,7 @@
        },
        "user_prompt_closed": {
         "beforeunload.py": [
-         "6b2e788a05879aa6a2326196f415701d7449573d",
+         "ab16526fdb177417269ff93c2e3d8abfdf730e56",
          [
           null,
           {}
@@ -830599,7 +831361,7 @@
          ]
         ],
         "user_prompt_opened.py": [
-         "3a995b150388909587ee8ed834030574de1e4003",
+         "c24128004f73a8b09a61991837b1dad103f91789",
          [
           null,
           {}
@@ -830811,7 +831573,7 @@
       },
       "integration": {
        "cookies_with_network_events.py": [
-        "16ca358e23be51d2de3047fd28ec47b66ece4163",
+        "30ba8e3bd7b8009070c4a6c1739b43efc8235f50",
         [
          null,
          {}
@@ -831179,23 +831941,23 @@
          ]
         ]
        },
-       "set_cache_bypass": {
-        "contexts_tentative.py": [
-         "946d6d9a7eb4f2129de13bf3954b2939775943c9",
+       "set_cache_behavior": {
+        "contexts.py": [
+         "5872a7d12e0d63787616ac4275f2489e91ff570b",
          [
           null,
           {}
          ]
         ],
-        "invalid_tentative.py": [
-         "678d5d313f899718af2b52f24479b57b839ec216",
+        "invalid.py": [
+         "921db569d4f7f7f877116171a8f8753f84d53b24",
          [
           null,
           {}
          ]
         ],
-        "set_cache_bypass_tentative.py": [
-         "42166ef253bb954a7df3099287caed259f33a0ec",
+        "set_cache_behavior.py": [
+         "0d55d520c9636a688f32158a7d7e3fb48e599153",
          [
           null,
           {}
@@ -832908,7 +833670,7 @@
         ]
        ],
        "unhandled_prompt_behavior.py": [
-        "2df69b131ffae686fe2d9b49890e692f3ac8601d",
+        "05b0f9309162b0a35bba1200713bc0db14acee4f",
         [
          null,
          {
diff --git a/tests/wpt/meta/css/css-animations/display-none-prevents-starting-in-subtree.html.ini b/tests/wpt/meta/css/css-animations/display-none-prevents-starting-in-subtree.html.ini
new file mode 100644
index 00000000000..612a75448bb
--- /dev/null
+++ b/tests/wpt/meta/css/css-animations/display-none-prevents-starting-in-subtree.html.ini
@@ -0,0 +1,3 @@
+[display-none-prevents-starting-in-subtree.html]
+  [Elements in a "display: none" tree cannot start CSS Animations.]
+    expected: FAIL
diff --git a/tests/wpt/meta/css/css-color/animation/opacity-animation-ending-correctly-002.html.ini b/tests/wpt/meta/css/css-color/animation/opacity-animation-ending-correctly-002.html.ini
deleted file mode 100644
index eb3cf41a070..00000000000
--- a/tests/wpt/meta/css/css-color/animation/opacity-animation-ending-correctly-002.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[opacity-animation-ending-correctly-002.html]
-  expected: TIMEOUT
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-022.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-022.tentative.html.ini
new file mode 100644
index 00000000000..b9715bdcbcf
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-022.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-022.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-023.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-023.tentative.html.ini
new file mode 100644
index 00000000000..4de92d88f8a
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-023.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-023.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-024.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-024.tentative.html.ini
new file mode 100644
index 00000000000..b4f17815816
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-024.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-024.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-025.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-025.tentative.html.ini
new file mode 100644
index 00000000000..21c21386446
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-025.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-025.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-026.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-026.tentative.html.ini
new file mode 100644
index 00000000000..cc760d52775
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-026.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-026.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-027.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-027.tentative.html.ini
new file mode 100644
index 00000000000..72c0f91de75
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-027.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-027.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-017.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-017.tentative.html.ini
new file mode 100644
index 00000000000..50a860f5cff
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-017.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-017.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-018.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-018.tentative.html.ini
new file mode 100644
index 00000000000..cc12506ab76
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-018.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-018.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-019.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-019.tentative.html.ini
new file mode 100644
index 00000000000..0eb22442455
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-019.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-019.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-020.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-020.tentative.html.ini
new file mode 100644
index 00000000000..c4a3171091e
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-020.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-020.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-021.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-021.tentative.html.ini
new file mode 100644
index 00000000000..ec0dd2607ab
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-021.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-021.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-022.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-022.tentative.html.ini
new file mode 100644
index 00000000000..a4378bd91ec
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-022.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-022.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-023.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-023.tentative.html.ini
new file mode 100644
index 00000000000..be570e7abe9
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-023.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-023.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-024.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-024.tentative.html.ini
new file mode 100644
index 00000000000..cfa4a650a3a
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-024.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-024.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-025.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-025.tentative.html.ini
new file mode 100644
index 00000000000..c1786082c26
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-025.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-025.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-026.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-026.tentative.html.ini
new file mode 100644
index 00000000000..0ee497e3bcd
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-026.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-026.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-027.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-027.tentative.html.ini
new file mode 100644
index 00000000000..30b109549c3
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-027.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-027.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-028.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-028.tentative.html.ini
new file mode 100644
index 00000000000..465e96a5404
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-028.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-028.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-029.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-029.tentative.html.ini
new file mode 100644
index 00000000000..3f6611a7627
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-029.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-029.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-030.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-030.tentative.html.ini
new file mode 100644
index 00000000000..4fdd099a51a
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-030.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-030.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-031.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-031.tentative.html.ini
new file mode 100644
index 00000000000..2c233b1cacc
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-031.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-031.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-032.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-032.tentative.html.ini
new file mode 100644
index 00000000000..00093f16b28
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-auto-032.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-auto-032.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-with-abspos-012.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-with-abspos-012.tentative.html.ini
new file mode 100644
index 00000000000..2f746ad56f3
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-with-abspos-012.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-with-abspos-012.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-with-abspos-013.tentative.html.ini b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-with-abspos-013.tentative.html.ini
new file mode 100644
index 00000000000..f710874fa75
--- /dev/null
+++ b/tests/wpt/meta/css/css-overflow/line-clamp/line-clamp-with-abspos-013.tentative.html.ini
@@ -0,0 +1,2 @@
+[line-clamp-with-abspos-013.tentative.html]
+  expected: FAIL
diff --git a/tests/wpt/meta/css/css-transforms/transform-input-018.html.ini b/tests/wpt/meta/css/css-transforms/transform-input-018.html.ini
deleted file mode 100644
index f425dbe5f4a..00000000000
--- a/tests/wpt/meta/css/css-transforms/transform-input-018.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[transform-input-018.html]
-  expected: FAIL
diff --git a/tests/wpt/meta/css/css-transitions/pseudo-element-transform.html.ini b/tests/wpt/meta/css/css-transitions/pseudo-element-transform.html.ini
new file mode 100644
index 00000000000..67df2295e2e
--- /dev/null
+++ b/tests/wpt/meta/css/css-transitions/pseudo-element-transform.html.ini
@@ -0,0 +1,2 @@
+[pseudo-element-transform.html]
+  expected: TIMEOUT
diff --git a/tests/wpt/meta/css/css-transitions/transitions-retarget.html.ini b/tests/wpt/meta/css/css-transitions/transitions-retarget.html.ini
new file mode 100644
index 00000000000..72d9f209146
--- /dev/null
+++ b/tests/wpt/meta/css/css-transitions/transitions-retarget.html.ini
@@ -0,0 +1,3 @@
+[transitions-retarget.html]
+  [Retargeting a transition should cause the old transition to be cancelled]
+    expected: FAIL
diff --git a/tests/wpt/meta/css/css-values/calc-size/animation/interpolate-size-interpolation.html.ini b/tests/wpt/meta/css/css-values/calc-size/animation/interpolate-size-interpolation.html.ini
new file mode 100644
index 00000000000..3c23c23b88a
--- /dev/null
+++ b/tests/wpt/meta/css/css-values/calc-size/animation/interpolate-size-interpolation.html.ini
@@ -0,0 +1,2 @@
+[interpolate-size-interpolation.html]
+  expected: ERROR
diff --git a/tests/wpt/meta/css/css-values/calc-size/interpolate-size-computed.html.ini b/tests/wpt/meta/css/css-values/calc-size/interpolate-size-computed.html.ini
new file mode 100644
index 00000000000..ae2404f8a21
--- /dev/null
+++ b/tests/wpt/meta/css/css-values/calc-size/interpolate-size-computed.html.ini
@@ -0,0 +1,6 @@
+[interpolate-size-computed.html]
+  [Property interpolate-size value 'numeric-only']
+    expected: FAIL
+
+  [Property interpolate-size value 'allow-keywords']
+    expected: FAIL
diff --git a/tests/wpt/meta/css/css-values/calc-size/interpolate-size-parsing.html.ini b/tests/wpt/meta/css/css-values/calc-size/interpolate-size-parsing.html.ini
new file mode 100644
index 00000000000..61bfc890ca0
--- /dev/null
+++ b/tests/wpt/meta/css/css-values/calc-size/interpolate-size-parsing.html.ini
@@ -0,0 +1,6 @@
+[interpolate-size-parsing.html]
+  [e.style['interpolate-size'\] = "numeric-only" should set the property value]
+    expected: FAIL
+
+  [e.style['interpolate-size'\] = "allow-keywords" should set the property value]
+    expected: FAIL
diff --git a/tests/wpt/meta/css/css-values/vh_not_refreshing_on_chrome.html.ini b/tests/wpt/meta/css/css-values/vh_not_refreshing_on_chrome.html.ini
deleted file mode 100644
index 26435e28b09..00000000000
--- a/tests/wpt/meta/css/css-values/vh_not_refreshing_on_chrome.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[vh_not_refreshing_on_chrome.html]
-  expected: FAIL
diff --git a/tests/wpt/meta/css/cssom-view/MediaQueryListEvent.html.ini b/tests/wpt/meta/css/cssom-view/MediaQueryListEvent.html.ini
index b7e476a0830..9250d55022a 100644
--- a/tests/wpt/meta/css/cssom-view/MediaQueryListEvent.html.ini
+++ b/tests/wpt/meta/css/cssom-view/MediaQueryListEvent.html.ini
@@ -2,3 +2,6 @@
   expected: TIMEOUT
   [constructor of "change" event]
     expected: NOTRUN
+
+  [argument of onchange]
+    expected: TIMEOUT
diff --git a/tests/wpt/meta/dom/observable/tentative/observable-constructor.any.js.ini b/tests/wpt/meta/dom/observable/tentative/observable-constructor.any.js.ini
index 3997fbb757a..8221c036594 100644
--- a/tests/wpt/meta/dom/observable/tentative/observable-constructor.any.js.ini
+++ b/tests/wpt/meta/dom/observable/tentative/observable-constructor.any.js.ini
@@ -110,6 +110,15 @@
   [Subscriber#error() value is stored as Subscriber's AbortSignal's reason]
     expected: FAIL
 
+  [Teardowns are called in upstream->downstream order on consumer-initiated unsubscription]
+    expected: FAIL
+
+  [Teardowns are called in downstream->upstream order on consumer-initiated unsubscription with pre-aborted Signal]
+    expected: FAIL
+
+  [Producer-initiated unsubscription in a downstream Observable fires abort events before each teardown, in downstream->upstream order]
+    expected: FAIL
+
 
 [observable-constructor.any.html]
   [Observable constructor]
@@ -222,3 +231,12 @@
 
   [Subscriber#error() value is stored as Subscriber's AbortSignal's reason]
     expected: FAIL
+
+  [Teardowns are called in upstream->downstream order on consumer-initiated unsubscription]
+    expected: FAIL
+
+  [Teardowns are called in downstream->upstream order on consumer-initiated unsubscription with pre-aborted Signal]
+    expected: FAIL
+
+  [Producer-initiated unsubscription in a downstream Observable fires abort events before each teardown, in downstream->upstream order]
+    expected: FAIL
diff --git a/tests/wpt/meta/fetch/metadata/generated/element-img-environment-change.sub.html.ini b/tests/wpt/meta/fetch/metadata/generated/element-img-environment-change.sub.html.ini
index 410ec4c1d39..4648085f98d 100644
--- a/tests/wpt/meta/fetch/metadata/generated/element-img-environment-change.sub.html.ini
+++ b/tests/wpt/meta/fetch/metadata/generated/element-img-environment-change.sub.html.ini
@@ -41,3 +41,6 @@
 
   [sec-fetch-site - HTTPS downgrade-upgrade, no attributes]
     expected: NOTRUN
+
+  [sec-fetch-site - Not sent to non-trustworthy same-origin destination, no attributes]
+    expected: FAIL
diff --git a/tests/wpt/meta/html/browsers/history/the-history-interface/traverse_the_history_3.html.ini b/tests/wpt/meta/html/browsers/history/the-history-interface/traverse_the_history_3.html.ini
deleted file mode 100644
index a03a8322165..00000000000
--- a/tests/wpt/meta/html/browsers/history/the-history-interface/traverse_the_history_3.html.ini
+++ /dev/null
@@ -1,3 +0,0 @@
-[traverse_the_history_3.html]
-  [Multiple history traversals, last would be aborted]
-    expected: FAIL
diff --git a/tests/wpt/meta/html/browsers/windows/embedded-opener-remove-frame.html.ini b/tests/wpt/meta/html/browsers/windows/embedded-opener-remove-frame.html.ini
index 91030fe2f7f..c43a5aa58f3 100644
--- a/tests/wpt/meta/html/browsers/windows/embedded-opener-remove-frame.html.ini
+++ b/tests/wpt/meta/html/browsers/windows/embedded-opener-remove-frame.html.ini
@@ -1,5 +1,4 @@
 [embedded-opener-remove-frame.html]
-  expected: CRASH
   [opener of discarded nested browsing context]
     expected: FAIL
 
diff --git a/tests/wpt/meta/html/browsers/windows/post-message/first-party-to-third-party-cross-partition-cross-origin.sub.html.ini b/tests/wpt/meta/html/browsers/windows/post-message/first-party-to-third-party-cross-partition-cross-origin.sub.html.ini
deleted file mode 100644
index 283c44174a7..00000000000
--- a/tests/wpt/meta/html/browsers/windows/post-message/first-party-to-third-party-cross-partition-cross-origin.sub.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[first-party-to-third-party-cross-partition-cross-origin.sub.html]
-  expected: TIMEOUT
-  [postMessage: First-Party to Third-Party, Cross-Partition, Cross-Origin]
-    expected: TIMEOUT
diff --git a/tests/wpt/meta/html/browsers/windows/post-message/first-party-to-third-party-cross-partition-same-origin.sub.html.ini b/tests/wpt/meta/html/browsers/windows/post-message/first-party-to-third-party-cross-partition-same-origin.sub.html.ini
deleted file mode 100644
index 762a134ed26..00000000000
--- a/tests/wpt/meta/html/browsers/windows/post-message/first-party-to-third-party-cross-partition-same-origin.sub.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[first-party-to-third-party-cross-partition-same-origin.sub.html]
-  expected: TIMEOUT
-  [postMessage: First-Party to Third-Party, Cross-Partition, Same-Origin]
-    expected: TIMEOUT
diff --git a/tests/wpt/meta/html/browsers/windows/post-message/third-party-to-third-party-cross-partition-cross-origin.sub.html.ini b/tests/wpt/meta/html/browsers/windows/post-message/third-party-to-third-party-cross-partition-cross-origin.sub.html.ini
deleted file mode 100644
index e211e6be83a..00000000000
--- a/tests/wpt/meta/html/browsers/windows/post-message/third-party-to-third-party-cross-partition-cross-origin.sub.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[third-party-to-third-party-cross-partition-cross-origin.sub.html]
-  expected: TIMEOUT
-  [postMessage: Third-Party to Third-Party, Cross-Partition, Cross-Origin]
-    expected: TIMEOUT
diff --git a/tests/wpt/meta/html/browsers/windows/post-message/third-party-to-third-party-cross-partition-same-origin.sub.html.ini b/tests/wpt/meta/html/browsers/windows/post-message/third-party-to-third-party-cross-partition-same-origin.sub.html.ini
deleted file mode 100644
index 488c6bd15d4..00000000000
--- a/tests/wpt/meta/html/browsers/windows/post-message/third-party-to-third-party-cross-partition-same-origin.sub.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[third-party-to-third-party-cross-partition-same-origin.sub.html]
-  expected: TIMEOUT
-  [postMessage: Third-Party to Third-Party, Cross-Partition, Same-Origin]
-    expected: TIMEOUT
diff --git a/tests/wpt/meta/html/browsers/windows/post-message/third-party-to-third-party-same-partition.sub.html.ini b/tests/wpt/meta/html/browsers/windows/post-message/third-party-to-third-party-same-partition.sub.html.ini
deleted file mode 100644
index 30607f12f29..00000000000
--- a/tests/wpt/meta/html/browsers/windows/post-message/third-party-to-third-party-same-partition.sub.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[third-party-to-third-party-same-partition.sub.html]
-  expected: TIMEOUT
-  [postMessage: Third-Party to Third-Party, Same-Partition]
-    expected: TIMEOUT
diff --git a/tests/wpt/meta/html/canvas/element/manual/imagebitmap/createImageBitmap-drawImage.html.ini b/tests/wpt/meta/html/canvas/element/manual/imagebitmap/createImageBitmap-drawImage.html.ini
index 6782931abac..c94490ae5ee 100644
--- a/tests/wpt/meta/html/canvas/element/manual/imagebitmap/createImageBitmap-drawImage.html.ini
+++ b/tests/wpt/meta/html/canvas/element/manual/imagebitmap/createImageBitmap-drawImage.html.ini
@@ -164,4 +164,3 @@
 
   [createImageBitmap from a vector HTMLImageElement scaled up, and drawImage on the created ImageBitmap]
     expected: FAIL
-
diff --git a/tests/wpt/meta/html/canvas/element/manual/imagebitmap/createImageBitmap-invalid-args.html.ini b/tests/wpt/meta/html/canvas/element/manual/imagebitmap/createImageBitmap-invalid-args.html.ini
index 74a99072845..2a3701b5bd0 100644
--- a/tests/wpt/meta/html/canvas/element/manual/imagebitmap/createImageBitmap-invalid-args.html.ini
+++ b/tests/wpt/meta/html/canvas/element/manual/imagebitmap/createImageBitmap-invalid-args.html.ini
@@ -1,5 +1,5 @@
 [createImageBitmap-invalid-args.html]
-  expected: ERROR
+  expected: TIMEOUT
   [createImageBitmap with a vector HTMLImageElement source and sw set to 0]
     expected: FAIL
 
diff --git a/tests/wpt/meta/html/canvas/element/text/2d.text.measure.caret-position-edge-cases.tentative.html.ini b/tests/wpt/meta/html/canvas/element/text/2d.text.measure.caret-position-edge-cases.tentative.html.ini
new file mode 100644
index 00000000000..751ca58fa7e
--- /dev/null
+++ b/tests/wpt/meta/html/canvas/element/text/2d.text.measure.caret-position-edge-cases.tentative.html.ini
@@ -0,0 +1,3 @@
+[2d.text.measure.caret-position-edge-cases.tentative.html]
+  [Test the edge cases for caretPositionFromPoint, where the point is at the edge of glyph and at the midpoint.]
+    expected: FAIL
diff --git a/tests/wpt/meta/html/canvas/element/text/2d.text.measure.caret-position-edges.tentative.html.ini b/tests/wpt/meta/html/canvas/element/text/2d.text.measure.caret-position-edges.tentative.html.ini
new file mode 100644
index 00000000000..a8f84833ae9
--- /dev/null
+++ b/tests/wpt/meta/html/canvas/element/text/2d.text.measure.caret-position-edges.tentative.html.ini
@@ -0,0 +1,30 @@
+[2d.text.measure.caret-position-edges.tentative.html]
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align left.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align left.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align center.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align center.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align right.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align right.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align start.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align start.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align end.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align end.]
+    expected: FAIL
diff --git a/tests/wpt/meta/html/canvas/element/text/2d.text.measure.caret-position.tentative.html.ini b/tests/wpt/meta/html/canvas/element/text/2d.text.measure.caret-position.tentative.html.ini
new file mode 100644
index 00000000000..2b7dea3b3b2
--- /dev/null
+++ b/tests/wpt/meta/html/canvas/element/text/2d.text.measure.caret-position.tentative.html.ini
@@ -0,0 +1,120 @@
+[2d.text.measure.caret-position.tentative.html]
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 10px letter spacing and directional-override.]
+    expected: FAIL
diff --git a/tests/wpt/meta/html/canvas/element/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.html.ini b/tests/wpt/meta/html/canvas/element/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.html.ini
new file mode 100644
index 00000000000..26263231bef
--- /dev/null
+++ b/tests/wpt/meta/html/canvas/element/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.html.ini
@@ -0,0 +1,2 @@
+[2d.text.measure.getActualBoundingBox-exceptions.tentative.html]
+  expected: ERROR
diff --git a/tests/wpt/meta/html/canvas/element/text/2d.text.measure.getActualBoundingBox-full-text.tentative.html.ini b/tests/wpt/meta/html/canvas/element/text/2d.text.measure.getActualBoundingBox-full-text.tentative.html.ini
new file mode 100644
index 00000000000..174591cf89f
--- /dev/null
+++ b/tests/wpt/meta/html/canvas/element/text/2d.text.measure.getActualBoundingBox-full-text.tentative.html.ini
@@ -0,0 +1,12 @@
+[2d.text.measure.getActualBoundingBox-full-text.tentative.html]
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction ltr and no-directional-override]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction rtl and no-directional-override]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction ltr and directional-override]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction rtl and directional-override]
+    expected: FAIL
diff --git a/tests/wpt/meta/html/canvas/element/text/2d.text.measure.getActualBoundingBox.tentative.html.ini b/tests/wpt/meta/html/canvas/element/text/2d.text.measure.getActualBoundingBox.tentative.html.ini
new file mode 100644
index 00000000000..fbde9c92f4b
--- /dev/null
+++ b/tests/wpt/meta/html/canvas/element/text/2d.text.measure.getActualBoundingBox.tentative.html.ini
@@ -0,0 +1,18 @@
+[2d.text.measure.getActualBoundingBox.tentative.html]
+  [Test TextMetrics::getActualBoundingBox(), with text align left , and 0px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align center , and 0px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align right , and 0px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align left , and 10px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align center , and 10px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align right , and 10px letter spacing.]
+    expected: FAIL
diff --git a/tests/wpt/meta/html/canvas/element/text/2d.text.measure.selection-rects.tentative.html.ini b/tests/wpt/meta/html/canvas/element/text/2d.text.measure.selection-rects.tentative.html.ini
index bd83dffdce1..26358feced0 100644
--- a/tests/wpt/meta/html/canvas/element/text/2d.text.measure.selection-rects.tentative.html.ini
+++ b/tests/wpt/meta/html/canvas/element/text/2d.text.measure.selection-rects.tentative.html.ini
@@ -1,3 +1,75 @@
 [2d.text.measure.selection-rects.tentative.html]
   [Check that TextMetrics::getSelectionRects() matches its DOM equivalent.]
     expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 10px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 10px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 10px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 10px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 10px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 10px letter spacing, and directional-override.]
+    expected: FAIL
diff --git a/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.caret-position-edge-cases.tentative.html.ini b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.caret-position-edge-cases.tentative.html.ini
new file mode 100644
index 00000000000..751ca58fa7e
--- /dev/null
+++ b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.caret-position-edge-cases.tentative.html.ini
@@ -0,0 +1,3 @@
+[2d.text.measure.caret-position-edge-cases.tentative.html]
+  [Test the edge cases for caretPositionFromPoint, where the point is at the edge of glyph and at the midpoint.]
+    expected: FAIL
diff --git a/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.caret-position-edge-cases.tentative.worker.js.ini b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.caret-position-edge-cases.tentative.worker.js.ini
new file mode 100644
index 00000000000..5d4cad8801f
--- /dev/null
+++ b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.caret-position-edge-cases.tentative.worker.js.ini
@@ -0,0 +1,3 @@
+[2d.text.measure.caret-position-edge-cases.tentative.worker.html]
+  [Test the edge cases for caretPositionFromPoint, where the point is at the edge of glyph and at the midpoint.]
+    expected: FAIL
diff --git a/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.caret-position-edges.tentative.html.ini b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.caret-position-edges.tentative.html.ini
new file mode 100644
index 00000000000..a8f84833ae9
--- /dev/null
+++ b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.caret-position-edges.tentative.html.ini
@@ -0,0 +1,30 @@
+[2d.text.measure.caret-position-edges.tentative.html]
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align left.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align left.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align center.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align center.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align right.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align right.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align start.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align start.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align end.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align end.]
+    expected: FAIL
diff --git a/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.caret-position-edges.tentative.worker.js.ini b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.caret-position-edges.tentative.worker.js.ini
new file mode 100644
index 00000000000..08ebd3f82f7
--- /dev/null
+++ b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.caret-position-edges.tentative.worker.js.ini
@@ -0,0 +1,30 @@
+[2d.text.measure.caret-position-edges.tentative.worker.html]
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align left.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align left.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align center.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align center.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align right.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align right.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align start.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align start.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align end.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align end.]
+    expected: FAIL
diff --git a/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.caret-position.tentative.html.ini b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.caret-position.tentative.html.ini
new file mode 100644
index 00000000000..2b7dea3b3b2
--- /dev/null
+++ b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.caret-position.tentative.html.ini
@@ -0,0 +1,120 @@
+[2d.text.measure.caret-position.tentative.html]
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 0px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 10px letter spacing and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 0px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 10px letter spacing and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 10px letter spacing and directional-override.]
+    expected: FAIL
diff --git a/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.html.ini b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.html.ini
new file mode 100644
index 00000000000..26263231bef
--- /dev/null
+++ b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.html.ini
@@ -0,0 +1,2 @@
+[2d.text.measure.getActualBoundingBox-exceptions.tentative.html]
+  expected: ERROR
diff --git a/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.worker.js.ini b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.worker.js.ini
new file mode 100644
index 00000000000..615275f70fe
--- /dev/null
+++ b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.worker.js.ini
@@ -0,0 +1,2 @@
+[2d.text.measure.getActualBoundingBox-exceptions.tentative.worker.html]
+  expected: TIMEOUT
diff --git a/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-full-text.tentative.html.ini b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-full-text.tentative.html.ini
new file mode 100644
index 00000000000..174591cf89f
--- /dev/null
+++ b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-full-text.tentative.html.ini
@@ -0,0 +1,12 @@
+[2d.text.measure.getActualBoundingBox-full-text.tentative.html]
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction ltr and no-directional-override]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction rtl and no-directional-override]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction ltr and directional-override]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction rtl and directional-override]
+    expected: FAIL
diff --git a/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-full-text.tentative.worker.js.ini b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-full-text.tentative.worker.js.ini
new file mode 100644
index 00000000000..2f1f2db1ce6
--- /dev/null
+++ b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-full-text.tentative.worker.js.ini
@@ -0,0 +1,12 @@
+[2d.text.measure.getActualBoundingBox-full-text.tentative.worker.html]
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction ltr and no-directional-override]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction rtl and no-directional-override]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction ltr and directional-override]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction rtl and directional-override]
+    expected: FAIL
diff --git a/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox.tentative.html.ini b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox.tentative.html.ini
new file mode 100644
index 00000000000..fbde9c92f4b
--- /dev/null
+++ b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox.tentative.html.ini
@@ -0,0 +1,18 @@
+[2d.text.measure.getActualBoundingBox.tentative.html]
+  [Test TextMetrics::getActualBoundingBox(), with text align left , and 0px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align center , and 0px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align right , and 0px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align left , and 10px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align center , and 10px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align right , and 10px letter spacing.]
+    expected: FAIL
diff --git a/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox.tentative.worker.js.ini b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox.tentative.worker.js.ini
new file mode 100644
index 00000000000..f3cc13a0b5e
--- /dev/null
+++ b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox.tentative.worker.js.ini
@@ -0,0 +1,18 @@
+[2d.text.measure.getActualBoundingBox.tentative.worker.html]
+  [Test TextMetrics::getActualBoundingBox(), with text align left , and 0px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align center , and 0px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align right , and 0px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align left , and 10px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align center , and 10px letter spacing.]
+    expected: FAIL
+
+  [Test TextMetrics::getActualBoundingBox(), with text align right , and 10px letter spacing.]
+    expected: FAIL
diff --git a/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.selection-rects.tentative.html.ini b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.selection-rects.tentative.html.ini
index bd83dffdce1..26358feced0 100644
--- a/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.selection-rects.tentative.html.ini
+++ b/tests/wpt/meta/html/canvas/offscreen/text/2d.text.measure.selection-rects.tentative.html.ini
@@ -1,3 +1,75 @@
 [2d.text.measure.selection-rects.tentative.html]
   [Check that TextMetrics::getSelectionRects() matches its DOM equivalent.]
     expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 0px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 10px letter spacing, and no-directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 0px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 10px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 10px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 10px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 10px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 10px letter spacing, and directional-override.]
+    expected: FAIL
+
+  [Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 10px letter spacing, and directional-override.]
+    expected: FAIL
diff --git a/tests/wpt/meta/html/dom/elements/global-attributes/cdata-dir_auto.html.ini b/tests/wpt/meta/html/dom/elements/global-attributes/cdata-dir_auto.html.ini
new file mode 100644
index 00000000000..e21e72894e5
--- /dev/null
+++ b/tests/wpt/meta/html/dom/elements/global-attributes/cdata-dir_auto.html.ini
@@ -0,0 +1,12 @@
+[cdata-dir_auto.html]
+  [Content of CDATA is ignored for dir=auto in html document]
+    expected: FAIL
+
+  [Text in CDATASection is considered when determining auto directionality]
+    expected: FAIL
+
+  [Directionality is updated when removing CDATASection]
+    expected: FAIL
+
+  [Directionality is updated when changing text of CDATASection]
+    expected: FAIL
diff --git a/tests/wpt/meta/html/dom/elements/global-attributes/dir-assorted.window.js.ini b/tests/wpt/meta/html/dom/elements/global-attributes/dir-assorted.window.js.ini
index 0daeceb99a1..1e6939b0478 100644
--- a/tests/wpt/meta/html/dom/elements/global-attributes/dir-assorted.window.js.ini
+++ b/tests/wpt/meta/html/dom/elements/global-attributes/dir-assorted.window.js.ini
@@ -118,3 +118,6 @@
 
   [non-html textarea element text contents influence dir=auto]
     expected: FAIL
+
+  [text changes apply to dir=auto on further ancestor after removing dir=ltr from closer ancestor]
+    expected: FAIL
diff --git a/tests/wpt/meta/html/dom/elements/global-attributes/dir-auto-dynamic-changes.window.js.ini b/tests/wpt/meta/html/dom/elements/global-attributes/dir-auto-dynamic-changes.window.js.ini
index 8becf694cfa..7395ce6f2ed 100644
--- a/tests/wpt/meta/html/dom/elements/global-attributes/dir-auto-dynamic-changes.window.js.ini
+++ b/tests/wpt/meta/html/dom/elements/global-attributes/dir-auto-dynamic-changes.window.js.ini
@@ -22,3 +22,27 @@
 
   [slotted non-HTML elements after dynamically assigning dir=auto, and dir attribute ignored on non-HTML elements]
     expected: FAIL
+
+  [dir=auto ancestor considers text in subtree after removing dir=ltr from it]
+    expected: FAIL
+
+  [Slotted content affects multiple dir=auto slots]
+    expected: FAIL
+
+  [Removing slotted content resets direction on dir=auto slot]
+    expected: FAIL
+
+  [Removing child of slotted content changes direction on dir=auto slot]
+    expected: FAIL
+
+  [Child directionality gets updated when dir=auto is set on parent]
+    expected: FAIL
+
+  [dir=auto slot is updated by text in value of input element children]
+    expected: FAIL
+
+  [dir=auto slot is updated if input stops being auto-directionality form-associated]
+    expected: FAIL
+
+  [slot provides updated directionality from host to a dir=auto container]
+    expected: FAIL
diff --git a/tests/wpt/meta/html/dom/elements/global-attributes/dir-slots-directionality.html.ini b/tests/wpt/meta/html/dom/elements/global-attributes/dir-slots-directionality.html.ini
index 2ff8bf31e7e..cd0a57e465c 100644
--- a/tests/wpt/meta/html/dom/elements/global-attributes/dir-slots-directionality.html.ini
+++ b/tests/wpt/meta/html/dom/elements/global-attributes/dir-slots-directionality.html.ini
@@ -25,3 +25,12 @@
 
   [slot with dir attribute is skipped by dir=auto]
     expected: FAIL
+
+  [dir=auto slot ignores dir attribute of assigned nodes]
+    expected: FAIL
+
+  [dir=auto slot considers text in bdi assigned nodes]
+    expected: FAIL
+
+  [dir=auto slot considers text in value of input element children]
+    expected: FAIL
diff --git a/tests/wpt/meta/html/semantics/embedded-content/media-elements/playing-the-media-resource/loop-from-ended.tentative.html.ini b/tests/wpt/meta/html/semantics/embedded-content/media-elements/playing-the-media-resource/loop-from-ended.tentative.html.ini
index cf8057c7fa8..6897533d946 100644
--- a/tests/wpt/meta/html/semantics/embedded-content/media-elements/playing-the-media-resource/loop-from-ended.tentative.html.ini
+++ b/tests/wpt/meta/html/semantics/embedded-content/media-elements/playing-the-media-resource/loop-from-ended.tentative.html.ini
@@ -5,4 +5,3 @@
 
   [play() with loop set to true after playback ended]
     expected: TIMEOUT
-
diff --git a/tests/wpt/meta/html/semantics/embedded-content/media-elements/track/track-element/no-cuechange-before-play.html.ini b/tests/wpt/meta/html/semantics/embedded-content/media-elements/track/track-element/no-cuechange-before-play.html.ini
index 4caf5931a11..246e55deb7e 100644
--- a/tests/wpt/meta/html/semantics/embedded-content/media-elements/track/track-element/no-cuechange-before-play.html.ini
+++ b/tests/wpt/meta/html/semantics/embedded-content/media-elements/track/track-element/no-cuechange-before-play.html.ini
@@ -1,3 +1,4 @@
 [no-cuechange-before-play.html]
+  expected: TIMEOUT
   [Ensure that the 'cuechange' event is not fired before video playback has begun.]
-    expected: FAIL
+    expected: TIMEOUT
diff --git a/tests/wpt/meta/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-1.html.ini b/tests/wpt/meta/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-1.html.ini
index d7e7d1b9815..f455bb20528 100644
--- a/tests/wpt/meta/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-1.html.ini
+++ b/tests/wpt/meta/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-1.html.ini
@@ -1,4 +1,4 @@
 [iframe_sandbox_popups_escaping-1.html]
   expected: CRASH
   [Check that popups from a sandboxed iframe escape the sandbox if\n       allow-popups-to-escape-sandbox is used]
-    expected: TIMEOUT
+    expected: FAIL
diff --git a/tests/wpt/meta/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-1.html.ini b/tests/wpt/meta/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-1.html.ini
index 96d866bf3cc..bbc1f35d8d9 100644
--- a/tests/wpt/meta/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-1.html.ini
+++ b/tests/wpt/meta/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-1.html.ini
@@ -1,4 +1,3 @@
 [iframe_sandbox_popups_nonescaping-1.html]
-  expected: TIMEOUT
   [Check that popups from a sandboxed iframe do not escape the sandbox]
     expected: FAIL
diff --git a/tests/wpt/meta/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-2.html.ini b/tests/wpt/meta/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-2.html.ini
index c6f1e5d7d84..a6591b318dc 100644
--- a/tests/wpt/meta/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-2.html.ini
+++ b/tests/wpt/meta/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-2.html.ini
@@ -1,4 +1,4 @@
 [iframe_sandbox_popups_nonescaping-2.html]
   expected: TIMEOUT
   [Check that popups from a sandboxed iframe do not escape the sandbox]
-    expected: NOTRUN
+    expected: FAIL
diff --git a/tests/wpt/meta/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-3.html.ini b/tests/wpt/meta/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-3.html.ini
index ccdaf8d61b2..ff6467094b8 100644
--- a/tests/wpt/meta/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-3.html.ini
+++ b/tests/wpt/meta/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-3.html.ini
@@ -1,3 +1,3 @@
 [iframe_sandbox_popups_nonescaping-3.html]
   [Check that popups from a sandboxed iframe do not escape the sandbox]
-    expected: NOTRUN
+    expected: FAIL
diff --git a/tests/wpt/meta/html/semantics/forms/form-submission-0/reparent-form-during-planned-navigation-task.html.ini b/tests/wpt/meta/html/semantics/forms/form-submission-0/reparent-form-during-planned-navigation-task.html.ini
deleted file mode 100644
index 7682a4830bf..00000000000
--- a/tests/wpt/meta/html/semantics/forms/form-submission-0/reparent-form-during-planned-navigation-task.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[reparent-form-during-planned-navigation-task.html]
-  expected: TIMEOUT
-  [reparent-form-during-planned-navigation-task]
-    expected: TIMEOUT
diff --git a/tests/wpt/meta/html/semantics/invokers/idlharness.tentative.html.ini b/tests/wpt/meta/html/semantics/invokers/idlharness.tentative.html.ini
index f9d4b78a7c6..cd96793eab1 100644
--- a/tests/wpt/meta/html/semantics/invokers/idlharness.tentative.html.ini
+++ b/tests/wpt/meta/html/semantics/invokers/idlharness.tentative.html.ini
@@ -34,3 +34,39 @@
 
   [InvokeEvent interface: new InvokeEvent("invoke") must inherit property "action" with the proper type]
     expected: FAIL
+
+  [CommandEvent interface: existence and properties of interface object]
+    expected: FAIL
+
+  [CommandEvent interface object length]
+    expected: FAIL
+
+  [CommandEvent interface object name]
+    expected: FAIL
+
+  [CommandEvent interface: existence and properties of interface prototype object]
+    expected: FAIL
+
+  [CommandEvent interface: existence and properties of interface prototype object's "constructor" property]
+    expected: FAIL
+
+  [CommandEvent interface: existence and properties of interface prototype object's @@unscopables property]
+    expected: FAIL
+
+  [CommandEvent interface: attribute invoker]
+    expected: FAIL
+
+  [CommandEvent interface: attribute command]
+    expected: FAIL
+
+  [CommandEvent must be primary interface of new CommandEvent("invoke")]
+    expected: FAIL
+
+  [Stringification of new CommandEvent("invoke")]
+    expected: FAIL
+
+  [CommandEvent interface: new CommandEvent("invoke") must inherit property "invoker" with the proper type]
+    expected: FAIL
+
+  [CommandEvent interface: new CommandEvent("invoke") must inherit property "command" with the proper type]
+    expected: FAIL
diff --git a/tests/wpt/meta/html/semantics/invokers/invokeelement-interface.tentative.html.ini b/tests/wpt/meta/html/semantics/invokers/invokeelement-interface.tentative.html.ini
index 587bdaf84d3..d04574db48e 100644
--- a/tests/wpt/meta/html/semantics/invokers/invokeelement-interface.tentative.html.ini
+++ b/tests/wpt/meta/html/semantics/invokers/invokeelement-interface.tentative.html.ini
@@ -43,3 +43,33 @@
 
   [invokeAction reflects '' when attribute set to [\]]
     expected: FAIL
+
+  [commandForElement reflects invokee HTML element]
+    expected: FAIL
+
+  [commandForElement reflects set value]
+    expected: FAIL
+
+  [commandForElement reflects set value across shadow root into light dom]
+    expected: FAIL
+
+  [commandForElement does not reflect set value inside shadowroot]
+    expected: FAIL
+
+  [commandForElement throws error on assignment of non Element]
+    expected: FAIL
+
+  [command reflects '' when attribute empty, setAttribute version]
+    expected: FAIL
+
+  [command reflects same casing]
+    expected: FAIL
+
+  [command reflects tostring value]
+    expected: FAIL
+
+  [command reflects '' when attribute set to [\]]
+    expected: FAIL
+
+  [command reflects tostring value 2]
+    expected: FAIL
diff --git a/tests/wpt/meta/resource-timing/test_resource_timing.https.html.ini b/tests/wpt/meta/resource-timing/test_resource_timing.https.html.ini
index dac51c99110..5a2e10ff69c 100644
--- a/tests/wpt/meta/resource-timing/test_resource_timing.https.html.ini
+++ b/tests/wpt/meta/resource-timing/test_resource_timing.https.html.ini
@@ -68,6 +68,3 @@
 
   [PerformanceEntry has correct protocol attribute (xmlhttprequest)]
     expected: FAIL
-
-  [PerformanceEntry has correct name, initiatorType, startTime, and duration (img)]
-    expected: FAIL
diff --git a/tests/wpt/tests/.github/workflows/docker.yml b/tests/wpt/tests/.github/workflows/docker.yml
index 32fb814e6d9..c6cb0ac58ef 100644
--- a/tests/wpt/tests/.github/workflows/docker.yml
+++ b/tests/wpt/tests/.github/workflows/docker.yml
@@ -40,7 +40,7 @@ jobs:
             latest
             type=raw,value=${{ inputs.tag }}
       - name: Build and push the Docker image
-        uses: docker/build-push-action@31159d49c0d4756269a0940a750801a1ea5d7003 # v6.1.0
+        uses: docker/build-push-action@15560696de535e4014efeff63c48f16952e52dd1 # v6.2.0
         with:
           context: ./tools/docker
           push: true
diff --git a/tests/wpt/tests/.taskcluster.yml b/tests/wpt/tests/.taskcluster.yml
index 38af7fa10af..85204ee17b9 100644
--- a/tests/wpt/tests/.taskcluster.yml
+++ b/tests/wpt/tests/.taskcluster.yml
@@ -57,7 +57,7 @@ tasks:
             owner: ${owner}
             source: ${event.repository.clone_url}
           payload:
-            image: webplatformtests/wpt:0.57
+            image: ghcr.io/web-platform-tests/wpt:1
             maxRunTime: 7200
             artifacts:
               public/results:
diff --git a/tests/wpt/tests/CODEOWNERS b/tests/wpt/tests/CODEOWNERS
index 140e0c6545b..07bda888b20 100644
--- a/tests/wpt/tests/CODEOWNERS
+++ b/tests/wpt/tests/CODEOWNERS
@@ -4,3 +4,7 @@
 
 # Prevent accidentally touching tools/third_party
 /tools/third_party/ @web-platform-tests/wpt-core-team
+
+# Require a review for Dockerfile
+tools/docker/Dockerfile @web-platform-tests/wpt-core-team @web-platform-tests/admins
+.taskcluster.yml @web-platform-tests/wpt-core-team @web-platform-tests/admins
diff --git a/tests/wpt/tests/accname/name/comp_tooltip.html b/tests/wpt/tests/accname/name/comp_tooltip.html
index deaabefd93a..c12f9c79fa0 100644
--- a/tests/wpt/tests/accname/name/comp_tooltip.html
+++ b/tests/wpt/tests/accname/name/comp_tooltip.html
@@ -49,7 +49,8 @@
 <!-- TODO: Move these: https://github.com/web-platform-tests/interop-accessibility/issues/78 -->
 <!-- https://w3c.github.io/html-aam/#text-level-element-accessible-name-computation -->
 <abbr title="Web Platform Tests" data-expectedlabel="Web Platform Tests" data-testname="abbr with tooltip label" class="ex">WPT</abbr>
-<kbd title="Control + Option" data-expectedlabel="Control + Option" data-testname="kbd with tooltip label" class="ex">CTRL + OPT</kbd>
+<!-- kbd test disabled: see resolution at https://github.com/web-platform-tests/interop-accessibility/issues/131 -->
+<!-- <kbd title="Control + Option" data-expectedlabel="Control + Option" data-testname="kbd with tooltip label" class="ex">CTRL + OPT</kbd> -->
 
 <!-- TODO: Move these: https://github.com/web-platform-tests/interop-accessibility/issues/78 -->
 <!-- https://w3c.github.io/html-aam/#summary-element-accessible-name-computation -->
@@ -66,4 +67,4 @@
 AriaUtils.verifyLabelsBySelector(".ex");
 </script>
 </body>
-</html>
\ No newline at end of file
+</html>
diff --git a/tests/wpt/tests/attribution-reporting/aggregatable-debug/simple-trigger-aggregatable-debug-report.sub.https.html b/tests/wpt/tests/attribution-reporting/aggregatable-debug/simple-trigger-aggregatable-debug-report.sub.https.html
index 4dbf7b39a7b..68eae824a29 100644
--- a/tests/wpt/tests/attribution-reporting/aggregatable-debug/simple-trigger-aggregatable-debug-report.sub.https.html
+++ b/tests/wpt/tests/attribution-reporting/aggregatable-debug/simple-trigger-aggregatable-debug-report.sub.https.html
@@ -11,6 +11,7 @@ attribution_reporting_promise_test(async t => {
   registerAttributionSrcByImg(createRedirectChain([
     {
       trigger: {
+        event_trigger_data: [{}],
         aggregatable_debug_reporting: {
           key_piece: '0x5',
           debug_data: [
diff --git a/tests/wpt/tests/credential-management/support/README.md b/tests/wpt/tests/credential-management/support/README.md
index a6d33ff6f75..f58d4cd0ce4 100644
--- a/tests/wpt/tests/credential-management/support/README.md
+++ b/tests/wpt/tests/credential-management/support/README.md
@@ -31,24 +31,3 @@ per engine:
 - function receive(): the main/only function that can be mocked
 - function expect(): the main/only function that enables us to mock it
 - enum State {kSuccess, kTimeout}: allows you to mock success/failures
-
-## FedCM Testing
-
-`fedcm-mojojs-helper.js` exposes `fedcm_mojo_mock_test` which is a specialized
-`promise_test` which comes pre-setup with the appropriate mocking infrastructure
-to emulate platform federated auth backend. The mock is passed to the test
-function as the second parameter.
-
-Example usage:
-```
-<script type="module">
-  import {fedcm_mojo_mock_test} from './support/fedcm-mojojs-helper.js';
-
-  fedcm_mojo_mock_test(async (t, mock) => {
-    mock.returnToken("https://idp.test/fedcm.json", "a_token");
-    assert_equals("a_token", await navigator.credentials.get(options));
-  }, "Successfully obtaining a token using mock.");
-</script>
-```
-
-The chromium implementation uses the MojoJS shim.
diff --git a/tests/wpt/tests/css/CSS2/floats/crashtests/firefox-bug-1906768.html b/tests/wpt/tests/css/CSS2/floats/crashtests/firefox-bug-1906768.html
new file mode 100644
index 00000000000..0300a90b206
--- /dev/null
+++ b/tests/wpt/tests/css/CSS2/floats/crashtests/firefox-bug-1906768.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<style>
+* {
+  line-break: anywhere;
+  columns: 66 0px;
+}
+#a {
+  float: right;
+}
+</style>
+<marquee>
+<input>
+<optgroup>a</optgroup>
+</marquee>
+<li>bbbbbbbbbbbbbbb</li>
+<li id="a">aaaaaaaaaaaaaaaaaa</li>
diff --git a/tests/wpt/tests/css/css-animations/display-none-prevents-starting-in-subtree.html b/tests/wpt/tests/css/css-animations/display-none-prevents-starting-in-subtree.html
new file mode 100644
index 00000000000..d5d48b2a184
--- /dev/null
+++ b/tests/wpt/tests/css/css-animations/display-none-prevents-starting-in-subtree.html
@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<link rel=author href="mailto:graouts@webkit.org">
+<link rel=help href="https://drafts.csswg.org/css-animations/#animations">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/css/css-animations/support/testcommon.js"></script>
+<style>
+@keyframes margin {
+    100% { margin-left: 200px }
+}
+
+#child {
+  animation: margin 1s forwards;
+}
+</style>
+<div id="container">
+    <div>
+        <div id="child"></div>
+    </div>
+</div>
+<script>
+test(() => {
+  const container = document.getElementById("container");
+  const animationCount = () => container.getAnimations({ subtree: true }).length;
+
+  assert_equals(animationCount(), 1, `An animation is running on the child initially with "display: block" on the container.`);
+
+  container.style.display = "none";
+  assert_equals(animationCount(), 0, `Setting "display: none" on the container canceled the animation.`);
+
+  container.style.marginLeft = "50px";
+  container.firstElementChild.style.marginLeft = "100px";
+  assert_equals(animationCount(), 0, `Manipulating styles on the container and a child element does not restart the animation.`);
+}, 'Elements in a "display: none" tree cannot start CSS Animations.');
+</script>
diff --git a/tests/wpt/tests/css/css-break/box-decoration-break-clone-005.tentative.html b/tests/wpt/tests/css/css-break/box-decoration-break-clone-005.tentative.html
new file mode 100644
index 00000000000..88ca6360f10
--- /dev/null
+++ b/tests/wpt/tests/css/css-break/box-decoration-break-clone-005.tentative.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<link rel="author" title="Morten Stenshorne" href="mailto:mstensho@chromium.org">
+<link rel="help" href="https://github.com/w3c/csswg-drafts/issues/10553">
+<meta name="assert" content="Test how an abspos contained by a block with cloned box decoration behaves.">
+<link rel="match" href="../reference/ref-filled-green-100px-square.xht">
+<p>Test passes if there is a filled green square and <strong>no red</strong>.</p>
+<div style="columns:2; column-fill:auto; gap:0; width:100px; height:100px; background:red;">
+  <!-- The expectation here (which might not be correct), is that the abspos
+       will start at the block-start padding edge of #container, and overlap
+       with cloned borders, although it fragments. Should it rather steer clear
+       of the cloned borders? -->
+  <div id="container" style="position:relative; box-decoration-break:clone; border:solid green; border-width:20px 0; border-bottom-color:red; padding:10px; height:80px;">
+    <div style="position:absolute; top:0; left:0; width:100%; height:180px; background:green;"></div>
+  </div>
+</div>
diff --git a/tests/wpt/tests/css/css-break/box-decoration-break-clone-006.html b/tests/wpt/tests/css/css-break/box-decoration-break-clone-006.html
new file mode 100644
index 00000000000..657f9f8442d
--- /dev/null
+++ b/tests/wpt/tests/css/css-break/box-decoration-break-clone-006.html
@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<link rel="author" title="Morten Stenshorne" href="mailto:mstensho@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-break/#break-decoration">
+<meta name="assert" content="Test how a float inside a block with cloned box decoration behaves.">
+<link rel="match" href="../reference/ref-filled-green-100px-square.xht">
+<p>Test passes if there is a filled green square and <strong>no red</strong>.</p>
+<div style="columns:4; column-fill:auto; gap:0; width:100px; height:100px; background:red;">
+  <!-- #container takes up exactly two columns (2 * 40px of box decorations in
+       each column, plus 40px of content box height). The float will steer clear
+       of its cloned border at the bottom of the first column and at the start
+       of the second column, but the border at the end of the second column is
+       just a regular end border, not a cloned one, so the float will overlap
+       with it. -->
+  <div id="container" style="box-decoration-break:clone; border:solid green; border-width:40px 0; height:40px;">
+    <div style="float:left; width:100%; height:280px; background:green;"></div>
+  </div>
+</div>
diff --git a/tests/wpt/tests/css/css-break/box-decoration-break-clone-007.html b/tests/wpt/tests/css/css-break/box-decoration-break-clone-007.html
new file mode 100644
index 00000000000..f2855edaff8
--- /dev/null
+++ b/tests/wpt/tests/css/css-break/box-decoration-break-clone-007.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<link rel="author" title="Morten Stenshorne" href="mailto:mstensho@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-break/#break-decoration">
+<meta name="assert" content="box-sizing:border-box and cloned box decorations.">
+<link rel="match" href="../reference/ref-filled-green-100px-square.xht">
+<p>Test passes if there is a filled green square and <strong>no red</strong>.</p>
+<div style="columns:2; column-fill:auto; gap:0; width:100px; height:100px; background:red;">
+  <div style="box-decoration-break:clone; border:10px solid green; box-sizing:border-box; height:200px; background:green;"></div>
+</div>
diff --git a/tests/wpt/tests/css/css-break/box-decoration-break-clone-008.html b/tests/wpt/tests/css/css-break/box-decoration-break-clone-008.html
new file mode 100644
index 00000000000..5f132318835
--- /dev/null
+++ b/tests/wpt/tests/css/css-break/box-decoration-break-clone-008.html
@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<link rel="author" title="Morten Stenshorne" href="mailto:mstensho@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-break/#break-decoration">
+<meta name="assert" content="Cloned box decorations, including margins.">
+<link rel="match" href="../reference/ref-filled-green-100px-square.xht">
+<p>Test passes if there is a filled green square and <strong>no red</strong>.</p>
+<div style="columns:2; column-fill:auto; gap:0; width:100px; height:100px; background:red;">
+  <div style="display:flow-root; background:green;">
+    <div style="box-decoration-break:clone; margin:10px 0; padding:10px 0;">
+      <div style="height:100px;"></div>
+    </div>
+    <div style="height:40px;"></div>
+  </div>
+</div>
diff --git a/tests/wpt/tests/css/css-break/box-decoration-break-clone-009-ref.html b/tests/wpt/tests/css/css-break/box-decoration-break-clone-009-ref.html
new file mode 100644
index 00000000000..23be78f87fc
--- /dev/null
+++ b/tests/wpt/tests/css/css-break/box-decoration-break-clone-009-ref.html
@@ -0,0 +1,7 @@
+<!DOCTYPE html>
+<link rel="author" title="Morten Stenshorne" href="mailto:mstensho@chromium.org">
+<p>There should be two squares below, with a hotpink outline and a cyan "shadow".</p>
+<div style="margin:20px; display:flex; width:230px; height:100px; justify-content:space-between;">
+  <div style="width:100px; height:100px; box-shadow:0 0 0 10px cyan; outline: 5px solid hotpink;"></div>
+  <div style="width:100px; height:100px; box-shadow:0 0 0 10px cyan; outline: 5px solid hotpink;"></div>
+</div>
diff --git a/tests/wpt/tests/css/css-break/box-decoration-break-clone-009.html b/tests/wpt/tests/css/css-break/box-decoration-break-clone-009.html
new file mode 100644
index 00000000000..1db904332ae
--- /dev/null
+++ b/tests/wpt/tests/css/css-break/box-decoration-break-clone-009.html
@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<link rel="author" title="Morten Stenshorne" href="mailto:mstensho@chromium.org">
+<link rel="help" href="https://drafts.csswg.org/css-break/#break-decoration">
+<meta name="assert" content="Cloned box decorations, with outline and shadow.">
+<link rel="match" href="box-decoration-break-clone-009-ref.html">
+<p>There should be two squares below, with a hotpink outline and a cyan "shadow".</p>
+<div style="margin:20px; columns:2; gap:30px; column-fill:auto; width:230px; height:100px;">
+  <div style="box-decoration-break:clone; height:200px; box-shadow:0 0 0 10px cyan; outline: 5px solid hotpink;">
+  </div>
+</div>
diff --git a/tests/wpt/tests/css/css-color/color-mix-non-srgb-001-ref.html b/tests/wpt/tests/css/css-color/color-mix-non-srgb-001-ref.html
index 15556737c7f..e143350866d 100644
--- a/tests/wpt/tests/css/css-color/color-mix-non-srgb-001-ref.html
+++ b/tests/wpt/tests/css/css-color/color-mix-non-srgb-001-ref.html
@@ -1,6 +1,6 @@
 <!DOCTYPE html>
 <meta charset="utf-8">
-<link rel="author" href="mailto:barret@brennie.ca" title="Barret Rennie">
+<link rel="author" href="mailto:beth@brennie.ca" title="Beth Rennie">
 <link rel="author" href="https://mozilla.org" title="Mozilla">
 <style>
 div { color: black; }
diff --git a/tests/wpt/tests/css/css-color/color-mix-non-srgb-001.html b/tests/wpt/tests/css/css-color/color-mix-non-srgb-001.html
index 7563581a4cf..550a919d241 100644
--- a/tests/wpt/tests/css/css-color/color-mix-non-srgb-001.html
+++ b/tests/wpt/tests/css/css-color/color-mix-non-srgb-001.html
@@ -2,7 +2,7 @@
 <meta charset="utf-8">
 <link rel="help" href="https://drafts.csswg.org/css-color-5/#color-mix">
 <link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1703356">
-<link rel="author" href="mailto:barret@brennie.ca" title="Barret Rennie">
+<link rel="author" href="mailto:beth@brennie.ca" title="Beth Rennie">
 <link rel="author" href="https://mozilla.org" title="Mozilla">
 <link rel="match" href="./color-mix-non-srgb-001-ref.html">
 <style>
diff --git a/tests/wpt/tests/css/css-contain/content-visibility/content-visibility-auto-print-ref.html b/tests/wpt/tests/css/css-contain/content-visibility/content-visibility-auto-print-ref.html
new file mode 100644
index 00000000000..6f500daa743
--- /dev/null
+++ b/tests/wpt/tests/css/css-contain/content-visibility/content-visibility-auto-print-ref.html
@@ -0,0 +1,4 @@
+<!doctype html>
+<meta charset=utf-8>
+<div style="height: 500px"></div>
+<div>Hello World</div>
diff --git a/tests/wpt/tests/css/css-contain/content-visibility/content-visibility-auto-print.html b/tests/wpt/tests/css/css-contain/content-visibility/content-visibility-auto-print.html
new file mode 100644
index 00000000000..35bc333e879
--- /dev/null
+++ b/tests/wpt/tests/css/css-contain/content-visibility/content-visibility-auto-print.html
@@ -0,0 +1,8 @@
+<!doctype html>
+<meta charset=utf-8>
+<link rel=match href="content-visibility-auto-print-ref.html">
+<link rel=help href="https://drafts.csswg.org/css-contain/#content-visibility">
+<link rel=help href="https://bugzilla.mozilla.org/show_bug.cgi?id=1907081">
+<!-- Pushes the following link onto page 3 of the print output: -->
+<div style="height: 500px"></div>
+<div style="content-visibility: auto">Hello World</div>
diff --git a/tests/wpt/tests/css/css-contain/content-visibility/content-visibility-auto-svg-image-ref.html b/tests/wpt/tests/css/css-contain/content-visibility/content-visibility-auto-svg-image-ref.html
new file mode 100644
index 00000000000..39939a6b33b
--- /dev/null
+++ b/tests/wpt/tests/css/css-contain/content-visibility/content-visibility-auto-svg-image-ref.html
@@ -0,0 +1,11 @@
+<!doctype html>
+<meta charset=utf-8>
+<body>
+    <svg xmlns="http://www.w3.org/2000/svg" width="400" height="100">
+        <foreignObject width="100%" height="100%">
+          <div xmlns="http://www.w3.org/1999/xhtml" style="content-visibility: auto;">
+            <p style="font: 50px sans-serif;">Hello World</p>
+          </div>
+        </foreignObject>
+    </svg>
+</body>
diff --git a/tests/wpt/tests/css/css-contain/content-visibility/content-visibility-auto-svg-image.html b/tests/wpt/tests/css/css-contain/content-visibility/content-visibility-auto-svg-image.html
new file mode 100644
index 00000000000..46de764072d
--- /dev/null
+++ b/tests/wpt/tests/css/css-contain/content-visibility/content-visibility-auto-svg-image.html
@@ -0,0 +1,25 @@
+<!doctype html>
+<meta charset=utf-8>
+<link rel=match href="content-visibility-auto-svg-image-ref.html">
+<link rel=help href="https://drafts.csswg.org/css-contain/#content-visibility">
+<link rel=help href="https://bugzilla.mozilla.org/show_bug.cgi?id=1894546">
+<body>
+
+<script>
+const svg = `
+    <svg xmlns="http://www.w3.org/2000/svg" width="400" height="100">
+        <foreignObject width="100%" height="100%">
+          <div xmlns="http://www.w3.org/1999/xhtml" style="content-visibility: auto;">
+            <p style="font: 50px sans-serif;">Hello World</p>
+          </div>
+        </foreignObject>
+    </svg>`;
+
+const data = `data:image/svg+xml,${encodeURIComponent(svg)}`;
+const svgImage = new Image();
+svgImage.src = data;
+
+document.body.appendChild(svgImage);
+</script>
+
+</body>
diff --git a/tests/wpt/tests/css/css-masking/clip-path/animations/clip-path-animation-cancel-ref.html b/tests/wpt/tests/css/css-masking/clip-path/animations/clip-path-animation-cancel-ref.html
new file mode 100644
index 00000000000..661e7b3be84
--- /dev/null
+++ b/tests/wpt/tests/css/css-masking/clip-path/animations/clip-path-animation-cancel-ref.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<style>
+  .container {
+    width: 100px;
+    height: 100px;
+    background-color: green;
+    clip-path: circle(20% at 20% 20%);
+  }
+</style>
+
+<body>
+  <div class="container"></div>
+</body>
+
+</html>
diff --git a/tests/wpt/tests/css/css-masking/clip-path/animations/clip-path-animation-cancel.html b/tests/wpt/tests/css/css-masking/clip-path/animations/clip-path-animation-cancel.html
new file mode 100644
index 00000000000..f92a016662b
--- /dev/null
+++ b/tests/wpt/tests/css/css-masking/clip-path/animations/clip-path-animation-cancel.html
@@ -0,0 +1,41 @@
+<!DOCTYPE html>
+<html class="reftest-wait">
+<link rel="help" href="https://drafts.csswg.org/css-shapes-1/#basic-shape-interpolation">
+<link rel="match" href="clip-path-animation-cancel-ref.html">
+<style>
+  /* This test ensures that canceling an animation properly results in a
+     repaint. If this does not happen, the animation will remain stuck until
+     invalidated for another reason. */
+  .container {
+    width: 100px;
+    height: 100px;
+    background-color: green;
+    animation: clippath 10s;
+    clip-path: circle(20% at 20% 20%);
+  }
+
+  @keyframes clippath {
+    0% {
+      clip-path: circle(35% at 35% 35%);
+    }
+
+    100% {
+      clip-path: circle(50% at 50% 50%);
+    }
+  }
+</style>
+<script src="/common/reftest-wait.js"></script>
+<script src="/web-animations/resources/timing-utils.js"></script>
+
+<body>
+  <div class="container"></div>
+
+  <script>
+    document.getAnimations()[0].ready.then(() => {
+      document.getAnimations()[0].cancel();
+      requestAnimationFrame(takeScreenshot);
+    });
+  </script>
+</body>
+
+</html>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-022.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-022.tentative.html
new file mode 100644
index 00000000000..1ae5d94465a
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-022.tentative.html
@@ -0,0 +1,33 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: when clamping by lines, margins are respected</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/line-clamp-022-ref.html">
+<meta name="assert" content="When line-clamp is used with a number of lines, the box and its clamped children should be sized taking margins into account.">
+<style>
+.clamp {
+  line-clamp: 4;
+  font: 16px / 32px serif;
+  padding: 4px;
+  background-color: yellow;
+  border: 2px solid black;
+}
+.inner {
+  background-color: purple;
+  margin: 4px;
+  /* Having a border means the margins of the .inner boxes won't collapse */
+  border: 1px solid black;
+}
+.inner .inner {
+  background-color: orange;
+  white-space: pre;
+}
+</style>
+<div class="clamp"><div class="inner"><div class="inner">Line 1
+Line 2
+Line 3
+Line 4
+Line 5
+Line 6</div></div></div>
+<p>Following content.</p>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-023.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-023.tentative.html
new file mode 100644
index 00000000000..0e11ba4d862
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-023.tentative.html
@@ -0,0 +1,31 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: when clamping by lines, collapsed margins are respected</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/line-clamp-023-ref.html">
+<meta name="assert" content="When line-clamp is used with a number of lines, the box and its clamped children should be sized taking margin collapsing into account.">
+<style>
+.clamp {
+  line-clamp: 4;
+  font: 16px / 32px serif;
+  padding: 4px;
+  background-color: yellow;
+  border: 2px solid black;
+}
+.inner {
+  background-color: orange;
+  margin: 4px;
+  /* There is no border, so the margins of the .inner boxes will collapse */
+}
+.inner .inner {
+  white-space: pre;
+}
+</style>
+<div class="clamp"><div class="inner"><div class="inner">Line 1
+Line 2
+Line 3
+Line 4
+Line 5
+Line 6</div></div></div>
+<p>Following content.</p>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-024.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-024.tentative.html
new file mode 100644
index 00000000000..0efb474a11f
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-024.tentative.html
@@ -0,0 +1,46 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: when clamping by lines, margins of hidden boxes are ignored</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/line-clamp-022-ref.html">
+<meta name="assert" content="When line-clamp is used with a number of lines, the margins of boxes after the clamp point should not affect the sizing of boxes.">
+<style>
+.clamp {
+  line-clamp: 4;
+  font: 16px / 32px serif;
+  padding: 4px;
+  background-color: yellow;
+  border: 2px solid black;
+}
+.inner {
+  background-color: purple;
+  margin: 4px;
+  /* Having a border means the margins of the .inner boxes won't collapse */
+  border: 1px solid black;
+}
+.inner .inner {
+  background-color: orange;
+  white-space: pre;
+}
+.clamped-margin {
+  /* These boxes are after the clamp point, so their margins should not affect
+   * the size of their parent boxes. */
+  background-color: red;
+  margin: 20px;
+  height: 20px;
+}
+</style>
+<div class="clamp">
+<div class="inner">
+<div class="inner">Line 1
+Line 2
+Line 3
+Line 4
+Line 5
+Line 6</div>
+<div class="clamped-margin"></div>
+</div>
+<div class="clamped-margin"></div>
+</div>
+<p>Following content.</p>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-025.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-025.tentative.html
new file mode 100644
index 00000000000..b2a2c54f450
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-025.tentative.html
@@ -0,0 +1,44 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: when clamping by lines, margins of hidden boxes are ignored</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/line-clamp-023-ref.html">
+<meta name="assert" content="When line-clamp is used with a number of lines, the box and its clamped children should be sized taking margins into account.">
+<style>
+.clamp {
+  line-clamp: 4;
+  font: 16px / 32px serif;
+  padding: 4px;
+  background-color: yellow;
+  border: 2px solid black;
+}
+.inner {
+  background-color: orange;
+  margin: 4px;
+  /* There is no border, so the margins of the .inner boxes will collapse */
+}
+.inner .inner {
+  white-space: pre;
+}
+.clamped-margin {
+  /* These boxes are after the clamp point, so their margins should not affect
+   * the size of their parent boxes. */
+  background-color: red;
+  margin: 20px;
+  height: 20px;
+}
+</style>
+<div class="clamp">
+<div class="inner">
+<div class="inner">Line 1
+Line 2
+Line 3
+Line 4
+Line 5
+Line 6</div>
+<div class="clamped-margin"></div>
+</div>
+<div class="clamped-margin"></div>
+</div>
+<p>Following content.</p>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-026.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-026.tentative.html
new file mode 100644
index 00000000000..329d12d10bd
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-026.tentative.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: ruby annotations after the clamp point are not rendered</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/line-clamp-026-ref.html">
+<meta name="assert" content="Ruby annotations are part of a line box's content, and therefore must not be rendered if the line box wouldn't be">
+<style>
+.clamp {
+  line-clamp: 3;
+
+  font: 16px / 32px serif;
+  white-space: pre-wrap;
+}
+.ruby-under ruby {
+  ruby-position: under;
+}
+</style>
+<div class="clamp"><ruby>一<rt>いち</ruby><ruby>行<rt>ぎょう</ruby><ruby>目<rt>め</ruby>
+<span class="ruby-under"><ruby>ニ<rt>に</ruby><ruby>行<rt>ぎょう</ruby><ruby>目<rt>め</ruby></span>
+<ruby>三<rt><ruby>さん<rt>san</ruby></ruby><ruby>行<rt><ruby>ぎょう<rt>gyou</ruby></ruby><ruby>目<rt><ruby>め<rt>me</ruby></ruby>
+<ruby>四<rt>よん</ruby><ruby>行<rt>ぎょう</ruby><ruby>目<rt>め</ruby>
+<span class="ruby-under"><ruby>五<rt>ご</ruby><ruby>行<rt>ぎょう</ruby><ruby>目<rt>め</ruby></span>
+<ruby>六<rt><ruby>ろく<rt>roku</ruby></ruby><ruby>行<rt><ruby>ぎょう<rt>gyou</ruby></ruby><ruby>目<rt><ruby>め<rt>me</ruby></ruby></div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-027.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-027.tentative.html
new file mode 100644
index 00000000000..b2a376b2bd9
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-027.tentative.html
@@ -0,0 +1,27 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: sizing of line-clamp elements with ruby annotations</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/line-clamp-027-ref.html">
+<meta name="assert" content="The sizing of a line-clamp element should be exactly as if it had no content after clamp, even if there are ruby annotations involved.">
+<style>
+.clamp {
+  line-clamp: 3;
+  font-size: 16px / 16px serif;
+  white-space: pre-wrap;
+  background-color: yellow;
+}
+ruby.under {
+  ruby-position: under;
+}
+.large {
+  font-size: 3em;
+}
+</style>
+<div class="clamp">Line 1
+Line 2
+<ruby class="under">Line 3<rt>ruby</ruby>
+<ruby>Line 4<rt class="large">ruby</ruby>
+Line 5
+<ruby class="under">Line 6<rt class="large">ruby</ruby></div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-017.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-017.tentative.html
new file mode 100644
index 00000000000..376c69a2106
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-017.tentative.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: `line-clamp: auto` with the clamp point in a descendant</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/webkit-line-clamp-005-ref.html">
+<meta name="assert" content="line-clamp: auto should work when the clamp point is in a descendant block box">
+<style>
+.clamp {
+  line-clamp: auto;
+  max-height: 4lh;
+  font: 16px / 32px serif;
+  white-space: pre;
+  background-color: yellow;
+  padding: 0 4px;
+}
+</style>
+<div class="clamp"><div>Line 1
+Line 2
+Line 3
+Line 4
+Line 5
+Line 6</div></div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-018.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-018.tentative.html
new file mode 100644
index 00000000000..deb1f42431d
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-018.tentative.html
@@ -0,0 +1,26 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: `line-clamp: auto` with the clamp point in a descendant with bp</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/line-clamp-auto-018-ref.html">
+<meta name="assert" content="If line-clamp: auto has the clamp point in a descendant, it should take its border and padding into account">
+<style>
+.clamp {
+  line-clamp: auto;
+  max-height: 5lh;
+  font: 16px / 32px serif;
+  white-space: pre;
+  background-color: yellow;
+}
+.clamp > div {
+  padding: 2px;
+  border: 2px solid black;
+}
+</style>
+<div class="clamp"><div>Line 1
+Line 2
+Line 3
+Line 4
+Line 5
+Line 6</div></div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-019.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-019.tentative.html
new file mode 100644
index 00000000000..82c53dc6bbe
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-019.tentative.html
@@ -0,0 +1,27 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: `line-clamp: auto` with the clamp point in a descendant with bp</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/line-clamp-auto-019-ref.html">
+<meta name="assert" content="If line-clamp: auto has the clamp point in a descendant, it should take its border and padding into account">
+<style>
+.clamp {
+  line-clamp: auto;
+  max-height: 5lh;
+  font: 16px / 32px serif;
+  white-space: pre;
+  background-color: yellow;
+}
+.clamp > div {
+  /* The total block-size bp across the top and bottom is 2*(14+2) = 32px, same as the line-height */
+  padding: 14px;
+  border: 2px solid black;
+}
+</style>
+<div class="clamp"><div>Line 1
+Line 2
+Line 3
+Line 4
+Line 5
+Line 6</div></div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-020.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-020.tentative.html
new file mode 100644
index 00000000000..eb84151ca66
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-020.tentative.html
@@ -0,0 +1,27 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: `line-clamp: auto` with the clamp point in a descendant with bmp</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/line-clamp-auto-020-ref.html">
+<meta name="assert" content="If line-clamp: auto has the clamp point in a descendant, it should take its bmp into account">
+<style>
+.clamp {
+  line-clamp: auto;
+  max-height: 6lh;
+  font: 16px / 32px serif;
+  white-space: pre;
+  background-color: yellow;
+}
+.clamp > div {
+  /* The total block-size bpm across the top and bottom is 2*(15+2) = 34px, greater than the line-height */
+  padding: 15px;
+  border: 2px solid black;
+}
+</style>
+<div class="clamp"><div>Line 1
+Line 2
+Line 3
+Line 4
+Line 5
+Line 6</div></div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-021.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-021.tentative.html
new file mode 100644
index 00000000000..90c33755bee
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-021.tentative.html
@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: `line-clamp: auto` with multiple descendants</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/line-clamp-auto-021-ref.html">
+<meta name="assert" content="line-clamp: auto works well with multiple descendants">
+<style>
+.clamp {
+  line-clamp: auto;
+  max-height: 5lh;
+  font: 16px / 32px serif;
+  background-color: yellow;
+}
+.clamp > div {
+  /*
+   * The total border across the top and bottom of one element is 16px.
+   * The top and bottom borders across two elements add up to 32px = 1lh.
+   */
+  padding: 6px;
+  border: 2px solid black;
+  white-space: pre;
+}
+</style>
+<div class="clamp">
+<div>Line 1
+Line 2
+Line 3</div>
+<div>Line 4
+Line 5
+Line 6</div>
+<div>Line 7
+Line 8
+Line 9</div>
+</div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-022.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-022.tentative.html
new file mode 100644
index 00000000000..7834c9c3ae0
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-022.tentative.html
@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: `line-clamp: auto` with multiple descendants</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/line-clamp-auto-021-ref.html">
+<meta name="assert" content="line-clamp: auto works well with multiple descendants">
+<style>
+.clamp {
+  line-clamp: auto;
+  max-height: 5.5lh;
+  font: 16px / 32px serif;
+  background-color: yellow;
+}
+.clamp > div {
+  /*
+   * The total border across the top and bottom of one element is 16px.
+   * The top and bottom borders across two elements add up to 32px = 1lh.
+   */
+  padding: 6px;
+  border: 2px solid black;
+  white-space: pre;
+}
+</style>
+<div class="clamp">
+<div>Line 1
+Line 2
+Line 3</div>
+<div>Line 4
+Line 5
+Line 6</div>
+<div>Line 7
+Line 8
+Line 9</div>
+</div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-023.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-023.tentative.html
new file mode 100644
index 00000000000..d41d68d84a3
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-023.tentative.html
@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: `line-clamp: auto` with multiple descendants</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/line-clamp-auto-023-ref.html">
+<meta name="assert" content="line-clamp: auto works well with multiple descendants">
+<style>
+.clamp {
+  line-clamp: auto;
+  max-height: 7lh;
+  font: 16px / 32px serif;
+  background-color: yellow;
+}
+.clamp > div {
+  /*
+   * The total border across the top and bottom of one element is 16px.
+   * The top and bottom borders across two elements add up to 32px = 1lh.
+   */
+  padding: 6px;
+  border: 2px solid black;
+  white-space: pre;
+}
+</style>
+<div class="clamp">
+<div>Line 1
+Line 2
+Line 3</div>
+<div>Line 4
+Line 5
+Line 6</div>
+<div>Line 7
+Line 8
+Line 9</div>
+</div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-024.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-024.tentative.html
new file mode 100644
index 00000000000..134dade711a
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-024.tentative.html
@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: `line-clamp: auto` with multiple descendants</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/line-clamp-auto-023-ref.html">
+<meta name="assert" content="line-clamp: auto works well with multiple descendants">
+<style>
+.clamp {
+  line-clamp: auto;
+  max-height: 7.5lh;
+  font: 16px / 32px serif;
+  background-color: yellow;
+}
+.clamp > div {
+  /*
+   * The total border across the top and bottom of one element is 16px.
+   * The top and bottom borders across two elements add up to 32px = 1lh.
+   */
+  padding: 6px;
+  border: 2px solid black;
+  white-space: pre;
+}
+</style>
+<div class="clamp">
+<div>Line 1
+Line 2
+Line 3</div>
+<div>Line 4
+Line 5
+Line 6</div>
+<div>Line 7
+Line 8
+Line 9</div>
+</div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-025.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-025.tentative.html
new file mode 100644
index 00000000000..ee394b2a76d
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-025.tentative.html
@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: abspos exactly at the clamp point is visible</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/line-clamp-auto-025-ref.html">
+<meta name="assert" content="The chosen clamp point with line-clamp: auto is the last one where the box size doesn't overflow. Since non-inline abspos have a clamp point after them, and they don't take up any space in the container, an abspos right at the boundary should be visible.">
+<style>
+.clamp {
+  line-clamp: auto;
+  max-height: 4lh;
+  font: 16px / 32px serif;
+  background-color: yellow;
+}
+.inner {
+  white-space: pre-wrap;
+}
+.abspos {
+  position: absolute;
+  width: 100px;
+  height: 100px;
+  background-color: skyblue;
+}
+</style>
+
+<div class="clamp">
+<div class="inner">Line 1
+Line 2
+Line 3
+Line 4
+</div>
+<div class="abspos"></div>
+<div class="inner">Line 5
+Line 6</div>
+</div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-026.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-026.tentative.html
new file mode 100644
index 00000000000..f616cbed028
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-026.tentative.html
@@ -0,0 +1,40 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: abspos exactly at the clamp point is visible</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/line-clamp-auto-026-ref.html">
+<meta name="assert" content="The chosen clamp point with line-clamp: auto is the last one where the box size doesn't overflow. Since non-inline abspos have a clamp point after them, and they don't take up any space in the container, an abspos right at the boundary should be visible. If there's bottom padding in a container box, that counts as effectively shrinking the boundary.">
+<style>
+.clamp {
+  line-clamp: auto;
+  max-height: calc(4lh + 2 * 2px);
+  font: 16px / 32px serif;
+  background-color: yellow;
+}
+.padding {
+  padding: 2px;
+}
+.inner {
+  white-space: pre-wrap;
+}
+.abspos {
+  position: absolute;
+  width: 100px;
+  height: 100px;
+  background-color: skyblue;
+}
+</style>
+
+<div class="clamp">
+<div class="padding">
+<div class="inner">Line 1
+Line 2
+Line 3
+Line 4
+</div>
+<div class="abspos"></div>
+<div class="inner">Line 5
+Line 6</div>
+</div>
+</div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-027.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-027.tentative.html
new file mode 100644
index 00000000000..9ed461d8cfb
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-027.tentative.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: `line-clamp: auto` accounts for margin</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/line-clamp-auto-027-ref.html">
+<meta name="assert" content="With `line-clamp: auto`, if a clamp point might fall inside a box, its margins are accounted for.">
+<style>
+.clamp {
+  line-clamp: auto;
+  max-height: 6lh;
+  font: 16px / 32px serif;
+  white-space: pre;
+  background-color: yellow;
+}
+.clamp > div {
+  margin: 17px;
+}
+</style>
+<div class="clamp"><div>Line 1
+Line 2
+Line 3
+Line 4
+Line 5
+Line 6</div></div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-028.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-028.tentative.html
new file mode 100644
index 00000000000..e3bcf375bc5
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-028.tentative.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: `line-clamp: auto` accounts for margin</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/line-clamp-auto-028-ref.html">
+<meta name="assert" content="With `line-clamp: auto`, if a clamp point might fall inside a box, its margins are accounted for.">
+<style>
+.clamp {
+  line-clamp: auto;
+  max-height: 5lh;
+  font: 16px / 32px serif;
+  white-space: pre;
+  background-color: yellow;
+}
+.clamp > div {
+  margin: 16px;
+}
+</style>
+<div class="clamp"><div>Line 1
+Line 2
+Line 3
+Line 4
+Line 5
+Line 6</div></div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-029.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-029.tentative.html
new file mode 100644
index 00000000000..17a3f1a78c1
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-029.tentative.html
@@ -0,0 +1,26 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: `line-clamp: auto` accounts for collapsing margins</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/line-clamp-auto-029-ref.html">
+<meta name="assert" content="With `line-clamp: auto`, if a clamp point might fall inside a box, its margins are accounted for correctly, even if they collapse.">
+<style>
+.clamp {
+  line-clamp: auto;
+  max-height: 5lh;
+  font: 16px / 32px serif;
+  white-space: pre;
+  background-color: yellow;
+  margin: 4px;
+}
+.clamp div {
+  margin: 4px;
+}
+</style>
+<div class="clamp"><div><div><div>Line 1
+Line 2
+Line 3
+Line 4
+Line 5
+Line 6</div></div></div></div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-030.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-030.tentative.html
new file mode 100644
index 00000000000..2a3a73b3e71
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-030.tentative.html
@@ -0,0 +1,26 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: `line-clamp: auto` accounts for collapsing margins</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/line-clamp-auto-029-ref.html">
+<meta name="assert" content="With `line-clamp: auto`, if a clamp point might fall inside a box, its margins are accounted for correctly, even if they collapse.">
+<style>
+.clamp {
+  line-clamp: auto;
+  max-height: calc(4lh + 2 * 4px);
+  font: 16px / 32px serif;
+  white-space: pre;
+  background-color: yellow;
+  margin: 4px;
+}
+.clamp div {
+  margin: 4px;
+}
+</style>
+<div class="clamp"><div><div><div>Line 1
+Line 2
+Line 3
+Line 4
+Line 5
+Line 6</div></div></div></div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-031.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-031.tentative.html
new file mode 100644
index 00000000000..a723430c83e
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-031.tentative.html
@@ -0,0 +1,49 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: `line-clamp: auto` margin collapsing accounts for self-collapsing boxes</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/line-clamp-auto-031-ref.html">
+<meta name="assert" content="With `line-clamp: auto`, if a clamp point might fall inside a box, its margins are accounted for correctly. This is the case even for self-collapsing boxes before the clamp point.">
+<style>
+.clamp {
+  line-clamp: auto;
+  max-height: calc(4lh + 2 * 5px);
+  font: 16px / 32px serif;
+  background-color: orange;
+}
+.inner {
+  white-space: pre;
+  margin: 5px;
+  background-color: yellow;
+}
+.collapse-through {
+  margin: 10px;
+}
+.abspos {
+  position: absolute;
+  right: 0;
+  height: 100px;
+  width: 100px;
+  background-color: skyblue;
+}
+</style>
+
+<!--
+  The bottom margin of the first `.inner` ends at the clamp boundary, and the
+  bottom margin of `.collapse-through` ends after it. The clamp point therefore
+  is before `.collapse-through`, and so `.abpos` won't be visible.
+-->
+
+<div class="clamp">
+<div class="inner">Line 1
+Line 2
+Line 3
+Line 4</div>
+<div class="collapse-through"></div>
+<div class="abspos"></div>
+<div class="inner">Line 5
+Line 6
+Line 7
+Line 8</div>
+</div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-032.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-032.tentative.html
new file mode 100644
index 00000000000..17c6981ae33
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-auto-032.tentative.html
@@ -0,0 +1,50 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: `line-clamp: auto` margin collapsing accounts for self-collapsing boxes</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/line-clamp-auto-032-ref.html">
+<meta name="assert" content="With `line-clamp: auto`, if a clamp point might fall inside a box, its margins are accounted for correctly. This is the case even for self-collapsing boxes before the clamp point.">
+<style>
+.clamp {
+  line-clamp: auto;
+  max-height: calc(4lh + 2 * 5px);
+  font: 16px / 32px serif;
+  background-color: orange;
+}
+.inner {
+  white-space: pre;
+  margin: 5px;
+  background-color: yellow;
+}
+.collapse-through {
+  margin: 5px;
+}
+.abspos {
+  position: absolute;
+  right: 0;
+  height: 100px;
+  width: 100px;
+  background-color: skyblue;
+}
+</style>
+
+<!--
+  The bottom margins of both the first `.inner` and of `.collapse-through` end
+  at the clamp boundary, since the bottom margin of `.inner` collapses through
+  `.collapse-through`. This also puts the static position of `.abspos` at the
+  clamp boundary, which means it will be visible.
+-->
+
+<div class="clamp">
+<div class="inner">Line 1
+Line 2
+Line 3
+Line 4</div>
+<div class="collapse-through"></div>
+<div class="abspos"></div>
+<div class="inner">Line 5
+Line 6
+Line 7
+Line 8</div>
+</div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-with-abspos-012.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-with-abspos-012.tentative.html
new file mode 100644
index 00000000000..bed065f3838
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-with-abspos-012.tentative.html
@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: line-clamp: auto hidden block-level abspos</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/webkit-line-clamp-005-ref.html">
+<meta name="assert" content="Block-level abspos should still be hidden if it is after the clamp point with line-clamp: auto">
+<style>
+.clamp {
+  line-clamp: auto;
+  max-height: 4lh;
+  font: 16px / 32px serif;
+  padding: 0 4px;
+  background-color: yellow;
+}
+.inner {
+  white-space: pre;
+}
+.abspos {
+  position: absolute;
+  width: 100px;
+  height: 100px;
+  background-color: skyblue;
+}
+</style>
+
+<div class="clamp">
+<div class="inner">Line 1
+Line 2
+Line 3
+Line 4
+Line 5</div>
+<div class="inner">Line 6</div>
+<div class="abspos"></div>
+</div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-with-abspos-013.tentative.html b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-with-abspos-013.tentative.html
new file mode 100644
index 00000000000..ccea125f724
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/line-clamp-with-abspos-013.tentative.html
@@ -0,0 +1,36 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Overflow: line-clamp: auto hidden block-level abspos</title>
+<link rel="author" title="Andreu Botella" href="mailto:abotella@igalia.com">
+<link rel="help" href="https://drafts.csswg.org/css-overflow-4/#line-clamp">
+<link rel="match" href="reference/webkit-line-clamp-005-ref.html">
+<meta name="assert" content="Block-level abspos should still be hidden if it is after the clamp point with line-clamp: auto, even if it lies on the boundary because the automatic size of previous boxes was adjusted.">
+<style>
+.clamp {
+  line-clamp: auto;
+  max-height: 4lh;
+  font: 16px / 32px serif;
+  padding: 0 4px;
+  background-color: yellow;
+}
+.inner {
+  white-space: pre;
+}
+.abspos {
+  position: absolute;
+  width: 100px;
+  height: 100px;
+  background-color: skyblue;
+}
+</style>
+
+<div class="clamp">
+<div class="inner">Line 1
+Line 2
+Line 3
+Line 4
+Line 5
+Line 6
+</div>
+<div class="abspos"></div>
+</div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-022-ref.html b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-022-ref.html
new file mode 100644
index 00000000000..7df05662f07
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-022-ref.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Reference</title>
+<style>
+.clamp {
+  font: 16px / 32px serif;
+  padding: 4px;
+  background-color: yellow;
+  border: 2px solid black;
+}
+.inner {
+  background-color: purple;
+  margin: 4px;
+  border: 1px solid black;
+}
+.inner .inner {
+  background-color: orange;
+  white-space: pre;
+}
+</style>
+<div class="clamp"><div class="inner"><div class="inner">Line 1
+Line 2
+Line 3
+Line 4…</div></div></div>
+<p>Following content.</p>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-023-ref.html b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-023-ref.html
new file mode 100644
index 00000000000..55ca1ca92be
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-023-ref.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Reference</title>
+<style>
+.clamp {
+  font: 16px / 32px serif;
+  padding: 4px;
+  background-color: yellow;
+  border: 2px solid black;
+}
+.inner {
+  background-color: orange;
+  margin: 4px;
+}
+.inner .inner {
+  white-space: pre;
+}
+</style>
+<div class="clamp"><div class="inner"><div class="inner">Line 1
+Line 2
+Line 3
+Line 4…</div></div></div>
+<p>Following content.</p>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-026-ref.html b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-026-ref.html
new file mode 100644
index 00000000000..b6e816f997c
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-026-ref.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Reference</title>
+<style>
+.clamp {
+  font: 16px / 32px serif;
+  white-space: pre-wrap;
+}
+.ruby-under ruby {
+  ruby-position: under;
+}
+</style>
+<div class="clamp"><ruby>一<rt>いち</ruby><ruby>行<rt>ぎょう</ruby><ruby>目<rt>め</ruby>
+<span class="ruby-under"><ruby>ニ<rt>に</ruby><ruby>行<rt>ぎょう</ruby><ruby>目<rt>め</ruby></span>
+<ruby>三<rt><ruby>さん<rt>san</ruby></ruby><ruby>行<rt><ruby>ぎょう<rt>gyou</ruby></ruby><ruby>目<rt><ruby>め<rt>me</ruby></ruby>…</div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-027-ref.html b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-027-ref.html
new file mode 100644
index 00000000000..01ed862e0a2
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-027-ref.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Reference</title>
+<style>
+.clamp {
+  font-size: 16px / 16px serif;
+  white-space: pre-wrap;
+  background-color: yellow;
+}
+ruby.under {
+  ruby-position: under;
+}
+</style>
+<div class="clamp">Line 1
+Line 2
+<ruby class="under">Line 3<rt>ruby</ruby>…</div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-018-ref.html b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-018-ref.html
new file mode 100644
index 00000000000..4d24d766956
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-018-ref.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Reference</title>
+<style>
+.clamp {
+  display: flow-root;
+  font: 16px / 32px serif;
+  white-space: pre;
+  background-color: yellow;
+}
+.clamp > div {
+  padding: 2px;
+  border: 2px solid black;
+}
+</style>
+<div class="clamp"><div>Line 1
+Line 2
+Line 3
+Line 4…</div></div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-019-ref.html b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-019-ref.html
new file mode 100644
index 00000000000..5dd739a1dab
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-019-ref.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Reference</title>
+<style>
+.clamp {
+  display: flow-root;
+  font: 16px / 32px serif;
+  white-space: pre;
+  background-color: yellow;
+}
+.clamp > div {
+  padding: 14px;
+  border: 2px solid black;
+}
+</style>
+<div class="clamp"><div>Line 1
+Line 2
+Line 3
+Line 4…</div></div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-020-ref.html b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-020-ref.html
new file mode 100644
index 00000000000..ef111f1e4a8
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-020-ref.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Reference</title>
+<style>
+.clamp {
+  display: flow-root;
+  font: 16px / 32px serif;
+  white-space: pre;
+  background-color: yellow;
+}
+.clamp > div {
+  padding: 15px;
+  border: 2px solid black;
+}
+</style>
+<div class="clamp"><div>Line 1
+Line 2
+Line 3
+Line 4…</div></div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-021-ref.html b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-021-ref.html
new file mode 100644
index 00000000000..9ecad287453
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-021-ref.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Reference</title>
+<style>
+.clamp {
+  display: flow-root;
+  font: 16px / 32px serif;
+  background-color: yellow;
+}
+.clamp > div {
+  padding: 6px;
+  border: 2px solid black;
+  white-space: pre;
+}
+</style>
+<div class="clamp">
+<div>Line 1
+Line 2
+Line 3</div>
+<div>Line 4…</div>
+</div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-023-ref.html b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-023-ref.html
new file mode 100644
index 00000000000..adb4b6dc6ed
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-023-ref.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Reference</title>
+<style>
+.clamp {
+  display: flow-root;
+  font: 16px / 32px serif;
+  background-color: yellow;
+}
+.clamp > div {
+  padding: 6px;
+  border: 2px solid black;
+  white-space: pre;
+}
+</style>
+<div class="clamp">
+<div>Line 1
+Line 2
+Line 3</div>
+<div>Line 4
+Line 5
+Line 6…</div>
+</div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-025-ref.html b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-025-ref.html
new file mode 100644
index 00000000000..a76468d6d54
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-025-ref.html
@@ -0,0 +1,27 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Reference</title>
+<style>
+.clamp {
+  font: 16px / 32px serif;
+  background-color: yellow;
+}
+.inner {
+  white-space: pre-wrap;
+}
+.abspos {
+  position: absolute;
+  width: 100px;
+  height: 100px;
+  background-color: skyblue;
+}
+</style>
+
+<div class="clamp">
+<div class="inner">Line 1
+Line 2
+Line 3
+Line 4…
+</div>
+<div class="abspos"></div>
+</div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-026-ref.html b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-026-ref.html
new file mode 100644
index 00000000000..44d503a0522
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-026-ref.html
@@ -0,0 +1,32 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Reference</title>
+<style>
+.clamp {
+  font: 16px / 32px serif;
+  background-color: yellow;
+}
+.padding {
+  padding: 2px;
+}
+.inner {
+  white-space: pre-wrap;
+}
+.abspos {
+  position: absolute;
+  width: 100px;
+  height: 100px;
+  background-color: skyblue;
+}
+</style>
+
+<div class="clamp">
+<div class="padding">
+<div class="inner">Line 1
+Line 2
+Line 3
+Line 4…
+</div>
+<div class="abspos"></div>
+</div>
+</div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-027-ref.html b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-027-ref.html
new file mode 100644
index 00000000000..fa0ade7a61d
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-027-ref.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Reference</title>
+<style>
+.clamp {
+  display: flow-root;
+  font: 16px / 32px serif;
+  white-space: pre;
+  background-color: yellow;
+}
+.clamp > div {
+  margin: 17px;
+}
+</style>
+<div class="clamp"><div>Line 1
+Line 2
+Line 3
+Line 4…</div></div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-028-ref.html b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-028-ref.html
new file mode 100644
index 00000000000..b70c6be4ffc
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-028-ref.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Reference</title>
+<style>
+.clamp {
+  display: flow-root;
+  font: 16px / 32px serif;
+  white-space: pre;
+  background-color: yellow;
+}
+.clamp > div {
+  margin: 16px;
+}
+</style>
+<div class="clamp"><div>Line 1
+Line 2
+Line 3
+Line 4…</div></div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-029-ref.html b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-029-ref.html
new file mode 100644
index 00000000000..76cd5fb7d22
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-029-ref.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Reference</title>
+<style>
+.clamp {
+  display: flow-root;
+  font: 16px / 32px serif;
+  white-space: pre;
+  background-color: yellow;
+  margin: 4px;
+}
+.clamp div {
+  margin: 4px;
+}
+</style>
+<div class="clamp"><div><div><div>Line 1
+Line 2
+Line 3
+Line 4…</div></div></div></div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-031-ref.html b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-031-ref.html
new file mode 100644
index 00000000000..2d3c9d0261b
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-031-ref.html
@@ -0,0 +1,22 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Reference</title>
+<style>
+.clamp {
+  display: flow-root;
+  font: 16px / 32px serif;
+  background-color: orange;
+}
+.inner {
+  white-space: pre;
+  margin: 5px;
+  background-color: yellow;
+}
+</style>
+
+<div class="clamp">
+<div class="inner">Line 1
+Line 2
+Line 3
+Line 4…</div>
+</div>
diff --git a/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-032-ref.html b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-032-ref.html
new file mode 100644
index 00000000000..3b32f988cd9
--- /dev/null
+++ b/tests/wpt/tests/css/css-overflow/line-clamp/reference/line-clamp-auto-032-ref.html
@@ -0,0 +1,34 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>CSS Reference</title>
+<style>
+.clamp {
+  display: flow-root;
+  font: 16px / 32px serif;
+  background-color: orange;
+}
+.inner {
+  white-space: pre;
+  margin: 5px;
+  background-color: yellow;
+}
+.collapse-through {
+  margin: 5px;
+}
+.abspos {
+  position: absolute;
+  right: 0;
+  height: 100px;
+  width: 100px;
+  background-color: skyblue;
+}
+</style>
+
+<div class="clamp">
+<div class="inner">Line 1
+Line 2
+Line 3
+Line 4…</div>
+<div class="collapse-through"></div>
+<div class="abspos"></div>
+</div>
diff --git a/tests/wpt/tests/css/css-page/page-background-001-print-ref.html b/tests/wpt/tests/css/css-page/page-background-001-print-ref.html
new file mode 100644
index 00000000000..8269582d041
--- /dev/null
+++ b/tests/wpt/tests/css/css-page/page-background-001-print-ref.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<link rel="author" title="Morten Stenshorne" href="mailto:mstensho@chromium.org">
+<style>
+  body {
+    margin-left: 100px;
+  }
+</style>
+<img style="position:absolute; z-index:-1; top:0; left:0;" src="support/cat.png">
+There should be a cat in the top left corner on this page.
+<div style="break-before:page;">
+  But there should be no cat on this page.
+</div>
diff --git a/tests/wpt/tests/css/css-page/page-background-001-print.html b/tests/wpt/tests/css/css-page/page-background-001-print.html
new file mode 100644
index 00000000000..e1bc2196940
--- /dev/null
+++ b/tests/wpt/tests/css/css-page/page-background-001-print.html
@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<link rel="author" title="Morten Stenshorne" href="mailto:mstensho@chromium.org">
+<link rel="help" href="http://crbug.com/351332645">
+<link rel="match" href="page-background-001-print-ref.html">
+<style>
+  body {
+    margin-left: 100px;
+    background: url(support/cat.png) no-repeat;
+  }
+</style>
+There should be a cat in the top left corner on this page.
+<div style="break-before:page;">
+  But there should be no cat on this page.
+</div>
diff --git a/tests/wpt/tests/css/css-page/page-background-002-print-ref.html b/tests/wpt/tests/css/css-page/page-background-002-print-ref.html
new file mode 100644
index 00000000000..997a28c65ac
--- /dev/null
+++ b/tests/wpt/tests/css/css-page/page-background-002-print-ref.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<link rel="author" title="Morten Stenshorne" href="mailto:mstensho@chromium.org">
+<style>
+  @page {
+    size: 300px 50px;
+    margin: 0;
+  }
+  body {
+    margin-left: 100px;
+  }
+</style>
+<img style="position:absolute; z-index:-1; top:0; left:0;" src="support/cat.png">
+Cat head.
+<div style="break-before:page;">
+  Cat body.
+</div>
+<div style="break-before:page;">
+  No cat parts on this page.
+</div>
diff --git a/tests/wpt/tests/css/css-page/page-background-002-print.html b/tests/wpt/tests/css/css-page/page-background-002-print.html
new file mode 100644
index 00000000000..240d468ce44
--- /dev/null
+++ b/tests/wpt/tests/css/css-page/page-background-002-print.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<link rel="author" title="Morten Stenshorne" href="mailto:mstensho@chromium.org">
+<link rel="help" href="http://crbug.com/351332645">
+<link rel="match" href="page-background-002-print-ref.html">
+<style>
+  @page {
+    size: 300px 50px;
+    margin: 0;
+  }
+  body {
+    margin-left: 100px;
+    background: url(support/cat.png) no-repeat;
+  }
+</style>
+Cat head.
+<div style="break-before:page;">
+  Cat body.
+</div>
+<div style="break-before:page;">
+  No cat parts on this page.
+</div>
diff --git a/tests/wpt/tests/css/css-page/page-background-003-print-ref.html b/tests/wpt/tests/css/css-page/page-background-003-print-ref.html
new file mode 100644
index 00000000000..93f3c7e95ad
--- /dev/null
+++ b/tests/wpt/tests/css/css-page/page-background-003-print-ref.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<link rel="author" title="Morten Stenshorne" href="mailto:mstensho@chromium.org">
+<style>
+  @page {
+    size: 500px 250px;
+    margin: 0;
+  }
+  body {
+    margin-left: 100px;
+  }
+</style>
+<div style="position:absolute; z-index:-1; top:0; left:0; overflow:clip; contain:size; width:100px; height:500px;">
+  <img src="support/cat.png" style="display:block;">
+  <img src="support/cat.png" style="display:block;">
+  <img src="support/cat.png" style="display:block;">
+  <img src="support/cat.png" style="display:block;">
+  <img src="support/cat.png" style="display:block;">
+  <img src="support/cat.png" style="display:block;">
+</div>
+There should be two and a half cats on this page.
+<div style="break-before:page;">
+  There should be two and a half cats on this page, too (and the ears of another
+  cat barely visible at the bottom). The previous page ends with a cat's head,
+  and this page starts with a cat's body.
+</div>
diff --git a/tests/wpt/tests/css/css-page/page-background-003-print.html b/tests/wpt/tests/css/css-page/page-background-003-print.html
new file mode 100644
index 00000000000..fbc72ecd7d7
--- /dev/null
+++ b/tests/wpt/tests/css/css-page/page-background-003-print.html
@@ -0,0 +1,20 @@
+<!DOCTYPE html>
+<link rel="author" title="Morten Stenshorne" href="mailto:mstensho@chromium.org">
+<link rel="help" href="http://crbug.com/351332645">
+<link rel="match" href="page-background-003-print-ref.html">
+<style>
+  @page {
+    size: 500px 250px;
+    margin: 0;
+  }
+  body {
+    margin-left: 100px;
+    background: url(support/cat.png) repeat-y;
+  }
+</style>
+There should be two and a half cats on this page.
+<div style="break-before:page;">
+  There should be two and a half cats on this page, too (and the ears of another
+  cat barely visible at the bottom). The previous page ends with a cat's head,
+  and this page starts with a cat's body.
+</div>
diff --git a/tests/wpt/tests/css/css-properties-values-api/registered-property-computation-color-004.html b/tests/wpt/tests/css/css-properties-values-api/registered-property-computation-color-004.html
new file mode 100644
index 00000000000..66abd1b3c32
--- /dev/null
+++ b/tests/wpt/tests/css/css-properties-values-api/registered-property-computation-color-004.html
@@ -0,0 +1,22 @@
+<!DOCTYPE html>
+<link rel="help" href="https://drafts.csswg.org/css-properties-values-api/#calculation-of-computed-values" />
+<link rel="match" href="/css/reference/ref-filled-green-100px-square-only.html">
+<style>
+  @property --a {
+    syntax: '<color>';
+    inherits: true;
+    initial-value: green;
+  }
+
+  body {
+    --a: 1em;
+  }
+
+  div {
+    width: 100px;
+    height: 100px;
+    background-color: var(--a);
+  }
+</style>
+<p>Test passes if there is a filled green square.</p>
+<div></div>
diff --git a/tests/wpt/tests/css/css-tables/collapsed-border-remove-row-group-ref.html b/tests/wpt/tests/css/css-tables/collapsed-border-remove-row-group-ref.html
new file mode 100644
index 00000000000..060f0651b69
--- /dev/null
+++ b/tests/wpt/tests/css/css-tables/collapsed-border-remove-row-group-ref.html
@@ -0,0 +1,24 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>CSS test reference</title>
+<style>
+  table {
+    border-collapse: collapse;
+  }
+
+  td {
+    border-bottom: 10px solid;
+  }
+</style>
+<table>
+  <thead>
+    <tr>
+      <td>Something</td>
+    </tr>
+  </thead>
+  <tbody>
+    <tr>
+      <td>Body</td>
+    </tr>
+  </tbody>
+</table>
diff --git a/tests/wpt/tests/css/css-tables/collapsed-border-remove-row-group.html b/tests/wpt/tests/css/css-tables/collapsed-border-remove-row-group.html
new file mode 100644
index 00000000000..39b89956c54
--- /dev/null
+++ b/tests/wpt/tests/css/css-tables/collapsed-border-remove-row-group.html
@@ -0,0 +1,39 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>collapsed border recalculation as a result of removal</title>
+<link rel="author" href="mailto:emilio@crisal.io" title="Emilio Cobos Álvarez">
+<link rel="author" href="https://mozilla.org" title="Mozilla">
+<link rel="help" href="https://drafts.csswg.org/css-tables/#border-collapse-property">
+<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1907289">
+<link rel="match" href="collapsed-border-remove-row-group-ref.html">
+<style>
+  table {
+    border-collapse: collapse;
+  }
+  td {
+    border-bottom: 10px solid;
+  }
+</style>
+<table>
+  <thead>
+    <tr>
+      <td>Something</td>
+    </tr>
+  </thead>
+  <thead id="removeMe">
+    <tr>
+      <td style="border: 0">Something</td>
+    </tr>
+  </thead>
+  <tbody>
+    <tr>
+      <td>Body</td>
+    </tr>
+  </tbody>
+</table>
+<script>
+  onload = function () {
+    removeMe.getBoundingClientRect();
+    removeMe.remove();
+  };
+</script>
diff --git a/tests/wpt/tests/css/css-transitions/pseudo-element-transform-ref.html b/tests/wpt/tests/css/css-transitions/pseudo-element-transform-ref.html
new file mode 100644
index 00000000000..05ea20b69c4
--- /dev/null
+++ b/tests/wpt/tests/css/css-transitions/pseudo-element-transform-ref.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<html>
+<title>Reference for transition on pseudo-element</title>
+<link rel="help" href="http://www.w3.org/TR/CSS21/generate.html#before-after-content">
+<style>
+div {
+  width: 100px;
+  height: 100px;
+  background: rgb(255, 191, 0);
+}
+div::before {
+  content: "";
+  background: rgb(184, 115, 51);
+  width: 100px;
+  height: 100px;
+  transform: ScaleX(0.5);
+  display: block;
+  will-change: transform;
+}
+</style>
+<div></div>
diff --git a/tests/wpt/tests/css/css-transitions/pseudo-element-transform.html b/tests/wpt/tests/css/css-transitions/pseudo-element-transform.html
new file mode 100644
index 00000000000..1919835e3e0
--- /dev/null
+++ b/tests/wpt/tests/css/css-transitions/pseudo-element-transform.html
@@ -0,0 +1,52 @@
+<!DOCTYPE html>
+<html class="reftest-wait">
+<title>Transition on pseudo-element</title>
+<link rel="help" href="http://www.w3.org/TR/CSS21/generate.html#before-after-content">
+<link rel="match" href="pseudo-element-transform-ref.html">
+<script src="/common/reftest-wait.js"></script>
+<style>
+div {
+  width: 100px;
+  height: 100px;
+  background: rgb(255, 191, 0);
+}
+div::before {
+  content: "";
+  background: rgb(184, 115, 51);
+  width: 100px;
+  height: 100px;
+  transition-property: transform;
+  transition-duration: 10000s;
+  /* This timing-function has zero-slope at progress = 0.5 preventing drift */
+  transition-timing-function: cubic-bezier(0, 1, 1, 0);
+  transform: ScaleX(0);
+  /* Make the pseudo element "transformable" as per
+   * https://www.w3.org/TR/css-transforms-1/#transformable-element.
+   */
+  display: block;
+}
+
+div.animated::before {
+  transform: scaleX(1);
+}
+</style>
+<div></div>
+<script>
+// This is a regression test for crbug.com/40475833
+// Ported to WPT in an effort to prune browser-specific tests.
+window.onload = async () => {
+  requestAnimationFrame(() => {
+    const target = document.querySelector('div');
+    target.classList.add('animated');
+    const anim = document.getAnimations()[0];
+    anim.ready.then(() => {
+      const duration = anim.effect.getTiming().duration;
+      anim.currentTime = duration / 2;
+      requestAnimationFrame(() => {
+        requestAnimationFrame(takeScreenshot);
+      });
+    });
+  });
+};
+</script>
+</html>
diff --git a/tests/wpt/tests/css/css-transitions/transitions-retarget.html b/tests/wpt/tests/css/css-transitions/transitions-retarget.html
new file mode 100644
index 00000000000..ee4c54a0b19
--- /dev/null
+++ b/tests/wpt/tests/css/css-transitions/transitions-retarget.html
@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<title>Retargeted CSS transition</title>
+<link rel="help" href="https://www.w3.org/TR/css-transitions-1/#starting">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="element">x</div>
+<style>
+    #element {
+        transition: transform 2000ms;
+        transition-timing-function: linear;
+    }
+</style>
+<script>
+promise_test(function(t) {
+    element.offsetTop; // Force recalc
+    element.style.transform = "rotateX(180deg)";
+    element.offsetTop; // Force recalc
+
+    assert_equals(element.getAnimations().length, 1, 'Transition creates an animation');
+    var animation = element.getAnimations()[0];
+
+    return animation.ready.then(function() {
+        assert_equals(element.getAnimations().length, 1, 'No new animations yet');
+        assert_equals(element.getAnimations()[0], animation);
+
+        element.style.transform = "rotateX(360deg)";
+        element.offsetTop; // Force recalc
+
+        assert_equals(element.getAnimations().length, 1, 'Retargeting transition results in only one animation');
+
+        var newAnimation = element.getAnimations()[0];
+        assert_not_equals(newAnimation, animation);
+    });
+}, 'Retargeting a transition should cause the old transition to be cancelled');
+</script>
diff --git a/tests/wpt/tests/css/css-values/calc-size/animation/interpolate-size-interpolation.html b/tests/wpt/tests/css/css-values/calc-size/animation/interpolate-size-interpolation.html
new file mode 100644
index 00000000000..ef2034ba480
--- /dev/null
+++ b/tests/wpt/tests/css/css-values/calc-size/animation/interpolate-size-interpolation.html
@@ -0,0 +1,22 @@
+<!DOCTYPE html>
+<meta charset="UTF-8">
+<title>interpolate-size animations</title>
+<link rel="help" href="https://drafts.csswg.org/css-values-5/#calc-size">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/css/support/interpolation-testcommon.js"></script>
+<body>
+<script>
+  test_not_animatable({
+    property: 'interpolate-size',
+    from: 'numeric-only',
+    to: 'allow-keywords',
+    underlying: 'numeric-only',
+  });
+  test_not_animatable({
+    property: 'interpolate-size',
+    from: 'allow-keywords',
+    to: 'numeric-only',
+    underlying: 'numeric-only',
+  });
+</script>
diff --git a/tests/wpt/tests/css/css-values/calc-size/interpolate-size-computed.html b/tests/wpt/tests/css/css-values/calc-size/interpolate-size-computed.html
new file mode 100644
index 00000000000..ca7fd706cb9
--- /dev/null
+++ b/tests/wpt/tests/css/css-values/calc-size/interpolate-size-computed.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<meta charset="UTF-8">
+<title>The interpolate-size property: computed values</title>
+<link rel="help" href="https://drafts.csswg.org/css-values-5/#interpolate-size">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/css/support/computed-testcommon.js"></script>
+<div id="target"></div>
+<script>
+test_computed_value('interpolate-size', 'numeric-only');
+test_computed_value('interpolate-size', 'allow-keywords');
+</script>
diff --git a/tests/wpt/tests/css/css-values/calc-size/interpolate-size-parsing.html b/tests/wpt/tests/css/css-values/calc-size/interpolate-size-parsing.html
new file mode 100644
index 00000000000..04c8cff8f36
--- /dev/null
+++ b/tests/wpt/tests/css/css-values/calc-size/interpolate-size-parsing.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<meta charset="UTF-8">
+<title>The interpolate-size property: parsing</title>
+<link rel="help" href="https://drafts.csswg.org/css-values-5/#interpolate-size">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/css/support/parsing-testcommon.js"></script>
+
+<script>
+test_valid_value('interpolate-size', 'numeric-only');
+test_valid_value('interpolate-size', 'allow-keywords');
+
+test_invalid_value('interpolate-size', 'auto');
+test_invalid_value('interpolate-size', 'none');
+test_invalid_value('interpolate-size', '100%');
+</script>
diff --git a/tests/wpt/tests/custom-elements/form-associated/label-delegatesFocus.html b/tests/wpt/tests/custom-elements/form-associated/label-delegatesFocus.html
index 74d31363c98..6f854faeb66 100644
--- a/tests/wpt/tests/custom-elements/form-associated/label-delegatesFocus.html
+++ b/tests/wpt/tests/custom-elements/form-associated/label-delegatesFocus.html
@@ -11,6 +11,11 @@
   <my-custom-element id=custom></my-custom-element>
 </form>
 
+<form>
+  <label for=custom2><span>label</span></label>
+  <my-custom-element id=custom2></my-custom-element>
+</form>
+
 <script>
 class MyCustomElement extends HTMLElement {
   static formAssociated = true;
@@ -28,14 +33,25 @@ customElements.define('my-custom-element', MyCustomElement);
 window.onload = () => {
   promise_test(async () => {
     const label = document.querySelector('label');
-    const customElement = document.querySelector('my-custom-element');
+    const customElement = document.getElementById('custom');
     const input = customElement.shadowRoot.querySelector('input');
-    await new Promise((resolve) => {
-      input.addEventListener("focus", resolve, {once: true});
-      test_driver.click(label);
-    });
+    let focused = false;
+    input.addEventListener("focus", evt => { focused = true; }, {once: true});
+    await test_driver.click(label);
+    assert_true(focused, "should have received focus");
     assert_equals(document.activeElement, customElement);
     assert_equals(customElement.shadowRoot.activeElement, input);
   }, `Clicking on a label for a form associated custom element with delegatesFocus should focus the custom element's focus delegate.`);
+  promise_test(async () => {
+    const span = document.querySelector('span');
+    const customElement = document.getElementById('custom2');
+    const input = customElement.shadowRoot.querySelector('input');
+    let focused = false;
+    input.addEventListener("focus", evt => { focused = true; }, {once: true});
+    await test_driver.click(span);
+    assert_true(focused, "should have received focus");
+    assert_equals(document.activeElement, customElement);
+    assert_equals(customElement.shadowRoot.activeElement, input);
+  }, `Clicking on a span in a label for a form associated custom element with delegatesFocus should focus the custom element's focus delegate.`);
 };
 </script>
diff --git a/tests/wpt/tests/dom/nodes/moveBefore/tentative/input-moveBefore-crash.html b/tests/wpt/tests/dom/nodes/moveBefore/tentative/input-moveBefore-crash.html
new file mode 100644
index 00000000000..a41d06b024e
--- /dev/null
+++ b/tests/wpt/tests/dom/nodes/moveBefore/tentative/input-moveBefore-crash.html
@@ -0,0 +1,8 @@
+<!DOCTYPE html>
+<body>
+<input id="input">
+<script>
+window.onload = () => {
+    document.body.moveBefore(document.querySelector("#input"), null);
+};
+</script>
diff --git a/tests/wpt/tests/dom/observable/tentative/observable-constructor.any.js b/tests/wpt/tests/dom/observable/tentative/observable-constructor.any.js
index 2cd2ee2b664..109ed284db0 100644
--- a/tests/wpt/tests/dom/observable/tentative/observable-constructor.any.js
+++ b/tests/wpt/tests/dom/observable/tentative/observable-constructor.any.js
@@ -688,10 +688,26 @@ test(() => {
   assert_array_equals(results, ['subscribe() callback']);
   ac.abort();
   results.push('abort() returned');
+  // The reason the "inner" abort event handler is invoked first is because the
+  // "inner" AbortSignal is not a dependent signal (that would ordinarily get
+  // aborted after the parent, aka "outer" signal, is completely finished being
+  // aborted). Instead, the order of operations looks like this:
+  //   1. "Outer" signal begins to be aborted
+  //   2. Its abort algorithms [1] run [2]; the internal abort algorithm here is
+  //      the "inner" Subscriber's "Close a subscription" [0].
+  //      a. This signals abort on the "inner" Subscriber's signal, firing the
+  //         abort event
+  //      b. Then, the "inner" Subscriber's teardowns run.
+  //   3. Once the "outer" signal's abort algorithms are finished, the abort
+  //      event is fired [3], triggering the outer abort handler.
+  //
+  // [0]: https://wicg.github.io/observable/#close-a-subscription
+  // [1]: https://dom.spec.whatwg.org/#abortsignal-abort-algorithms
+  // [2]: https://dom.spec.whatwg.org/#ref-for-abortsignal-abort-algorithms%E2%91%A2:~:text=For%20each%20algorithm%20of%20signal%E2%80%99s%20abort%20algorithms%3A%20run%20algorithm
+  // [3]: https://dom.spec.whatwg.org/#abortsignal-signal-abort:~:text=Fire%20an%20event%20named%20abort%20at%20signal
   assert_array_equals(results, [
-      'subscribe() callback',
-      'outer abort handler', 'teardown 2', 'teardown 1',
-      'inner abort handler', 'abort() returned',
+      'subscribe() callback', 'inner abort handler', 'teardown 2', 'teardown 1',
+      'outer abort handler', 'abort() returned',
   ]);
   assert_false(activeDuringTeardown1, 'should not be active during teardown callback 1');
   assert_false(activeDuringTeardown2, 'should not be active during teardown callback 2');
@@ -699,6 +715,127 @@ test(() => {
   assert_true(abortedDuringTeardown2, 'should be aborted during teardown callback 2');
 }, "Unsubscription lifecycle");
 
+// In the usual consumer-initiated unsubscription case, when the AbortController
+// is aborted after subscription, teardowns run from upstream->downstream. This
+// is because for a given Subscriber, when a downstream signal is aborted
+// (`ac.signal` in this case), the "Close" algorithm prompts the Subscriber to
+// first abort *its* own signal (the one accessible via `Subscriber#signal`) and
+// then run its teardowns.
+//
+// This means upstream Subscribers get the first opportunity their teardowns
+// before the control flow is returned to downstream Subscribers to run *their*
+// teardowns (after they abort their internal signal).
+test(() => {
+  const results = [];
+  const upstream = new Observable(subscriber => {
+    subscriber.signal.addEventListener('abort',
+        e => results.push('upstream abort handler'), {once: true});
+    subscriber.addTeardown(
+        () => results.push(`upstream teardown. reason: ${subscriber.signal.reason}`));
+  });
+  const middle = new Observable(subscriber => {
+    subscriber.signal.addEventListener('abort',
+        e => results.push('middle abort handler'), {once: true});
+    subscriber.addTeardown(
+        () => results.push(`middle teardown. reason: ${subscriber.signal.reason}`));
+    upstream.subscribe({}, {signal: subscriber.signal});
+  });
+  const downstream = new Observable(subscriber => {
+    subscriber.signal.addEventListener('abort',
+        e => results.push('downstream abort handler'), {once: true});
+    subscriber.addTeardown(
+        () => results.push(`downstream teardown. reason: ${subscriber.signal.reason}`));
+    middle.subscribe({}, {signal: subscriber.signal});
+  });
+
+  const ac = new AbortController();
+  downstream.subscribe({}, {signal: ac.signal});
+  ac.abort('Abort!');
+  assert_array_equals(results, [
+      'upstream abort handler',
+      'upstream teardown. reason: Abort!',
+      'middle abort handler',
+      'middle teardown. reason: Abort!',
+      'downstream abort handler',
+      'downstream teardown. reason: Abort!',
+  ]);
+}, "Teardowns are called in upstream->downstream order on " +
+   "consumer-initiated unsubscription");
+
+// This test is like the above, but asserts the exact opposite order of
+// teardowns. This is because, since the Subscriber's signal is aborted
+// immediately upon construction, `addTeardown()` runs teardowns synchronously
+// in subscriber-order, which goes from downstream->upstream.
+test(() => {
+  const results = [];
+  const upstream = new Observable(subscriber => {
+    subscriber.addTeardown(
+        () => results.push(`upstream teardown. reason: ${subscriber.signal.reason}`));
+  });
+  const middle = new Observable(subscriber => {
+    subscriber.addTeardown(
+        () => results.push(`middle teardown. reason: ${subscriber.signal.reason}`));
+    upstream.subscribe({}, {signal: subscriber.signal});
+  });
+  const downstream = new Observable(subscriber => {
+    subscriber.addTeardown(
+        () => results.push(`downstream teardown. reason: ${subscriber.signal.reason}`));
+    middle.subscribe({}, {signal: subscriber.signal});
+  });
+
+  downstream.subscribe({}, {signal: AbortSignal.abort('Initial abort')});
+  assert_array_equals(results, [
+      "downstream teardown. reason: Initial abort",
+      "middle teardown. reason: Initial abort",
+      "upstream teardown. reason: Initial abort",
+  ]);
+}, "Teardowns are called in downstream->upstream order on " +
+   "consumer-initiated unsubscription with pre-aborted Signal");
+
+// Producer-initiated unsubscription test, capturing the ordering of abort events and teardowns.
+test(() => {
+  const results = [];
+
+  const source = new Observable(subscriber => {
+    subscriber.addTeardown(() => results.push('source teardown'));
+    subscriber.signal.addEventListener('abort',
+        e => results.push('source abort event'));
+  });
+
+  const middle = new Observable(subscriber => {
+    subscriber.addTeardown(() => results.push('middle teardown'));
+    subscriber.signal.addEventListener('abort',
+        e => results.push('middle abort event'));
+
+    source.subscribe(() => {}, {signal: subscriber.signal});
+  });
+
+  let innerSubscriber = null;
+  const downstream = new Observable(subscriber => {
+    innerSubscriber = subscriber;
+    subscriber.addTeardown(() => results.push('downstream teardown'));
+    subscriber.signal.addEventListener('abort',
+        e => results.push('downstream abort event'));
+
+    middle.subscribe(() => {}, {signal: subscriber.signal});
+  });
+
+  downstream.subscribe();
+
+  // Trigger a producer-initiated unsubscription from the most-downstream Observable.
+  innerSubscriber.complete();
+
+  assert_array_equals(results, [
+    'source abort event',
+    'source teardown',
+    'middle abort event',
+    'middle teardown',
+    'downstream abort event',
+    'downstream teardown',
+  ]);
+}, "Producer-initiated unsubscription in a downstream Observable fires abort " +
+   "events before each teardown, in downstream->upstream order");
+
 test(t => {
   let innerSubscriber = null;
   const source = new Observable(subscriber => {
diff --git a/tests/wpt/tests/dom/observable/tentative/observable-filter.any.js b/tests/wpt/tests/dom/observable/tentative/observable-filter.any.js
index 3c1a7d78248..419d59ed8a8 100644
--- a/tests/wpt/tests/dom/observable/tentative/observable-filter.any.js
+++ b/tests/wpt/tests/dom/observable/tentative/observable-filter.any.js
@@ -30,6 +30,7 @@ test(() => {
     subscriber.next(1);
     assert_true(teardownCalled, "Teardown called once map unsubscribes due to error");
     assert_false(subscriber.active, "Unsubscription makes Subscriber inactive");
+    results.push(subscriber.signal.reason);
     subscriber.next(2);
     subscriber.complete();
   });
@@ -44,7 +45,7 @@ test(() => {
       complete: () => results.push("complete"),
     });
 
-  assert_array_equals(results, [error]);
+  assert_array_equals(results, [error, error]);
 }, "filter(): Errors thrown in filter predicate are emitted to Observer error() handler");
 
 test(() => {
@@ -100,7 +101,7 @@ test(() => {
   });
 
   assert_array_equals(results,
-      ['source teardown', 'source abort event', 'filter observable complete']);
+      ['source abort event', 'source teardown', 'filter observable complete']);
 }, "filter(): Upon source completion, source Observable teardown sequence " +
    "happens after downstream filter complete() is called");
 
diff --git a/tests/wpt/tests/dom/observable/tentative/observable-first.any.js b/tests/wpt/tests/dom/observable/tentative/observable-first.any.js
index 7c99066dc22..d4738d7478b 100644
--- a/tests/wpt/tests/dom/observable/tentative/observable-first.any.js
+++ b/tests/wpt/tests/dom/observable/tentative/observable-first.any.js
@@ -94,8 +94,8 @@ promise_test(async () => {
     "calling first",
     "source subscribe",
     "before source next 1",
-    "source teardown",
     "source abort",
+    "source teardown",
     "after source next 1"
   ], "Array values after first() is called");
 
@@ -106,8 +106,8 @@ promise_test(async () => {
     "calling first",
     "source subscribe",
     "before source next 1",
-    "source teardown",
     "source abort",
+    "source teardown",
     "after source next 1",
     "first resolved with: 1",
   ], "Array values after Promise is awaited");
diff --git a/tests/wpt/tests/dom/observable/tentative/observable-last.any.js b/tests/wpt/tests/dom/observable/tentative/observable-last.any.js
index cd39a3700a2..064a781cada 100644
--- a/tests/wpt/tests/dom/observable/tentative/observable-last.any.js
+++ b/tests/wpt/tests/dom/observable/tentative/observable-last.any.js
@@ -91,8 +91,8 @@ promise_test(async () => {
     "before source next 1",
     "after source next 1",
     "before source complete",
-    "source teardown",
     "source abort",
+    "source teardown",
     "after source complete",
   ], "Array values after last() is called");
 
@@ -105,8 +105,8 @@ promise_test(async () => {
     "before source next 1",
     "after source next 1",
     "before source complete",
-    "source teardown",
     "source abort",
+    "source teardown",
     "after source complete",
     "last resolved with: 1",
   ], "Array values after Promise is awaited");
diff --git a/tests/wpt/tests/dom/observable/tentative/observable-map.any.js b/tests/wpt/tests/dom/observable/tentative/observable-map.any.js
index 275505fb5d0..a61c818bc16 100644
--- a/tests/wpt/tests/dom/observable/tentative/observable-map.any.js
+++ b/tests/wpt/tests/dom/observable/tentative/observable-map.any.js
@@ -132,7 +132,7 @@ test(() => {
   });
 
   assert_array_equals(results,
-      ['source teardown', 'source abort event', 'map observable complete']);
+      ['source abort event', 'source teardown', 'map observable complete']);
 }, "map(): Upon source completion, source Observable teardown sequence " +
    "happens before downstream mapper complete() is called");
 
diff --git a/tests/wpt/tests/dom/observable/tentative/observable-switchMap.any.js b/tests/wpt/tests/dom/observable/tentative/observable-switchMap.any.js
index 836a39a68e0..577ce2b748c 100644
--- a/tests/wpt/tests/dom/observable/tentative/observable-switchMap.any.js
+++ b/tests/wpt/tests/dom/observable/tentative/observable-switchMap.any.js
@@ -212,10 +212,10 @@ test(() => {
 
   ac.abort();
   assert_array_equals(results, [
-    "source teardown",
     "source onabort",
-    "inner teardown",
+    "source teardown",
     "inner onabort",
+    "inner teardown",
   ], "Unsubscription order is correct");
 }, "switchMap(): should unsubscribe in the correct order when user aborts " +
    "the subscription");
diff --git a/tests/wpt/tests/dom/observable/tentative/observable-takeUntil.any.js b/tests/wpt/tests/dom/observable/tentative/observable-takeUntil.any.js
index 2895dd31e3f..f2e99b8cbec 100644
--- a/tests/wpt/tests/dom/observable/tentative/observable-takeUntil.any.js
+++ b/tests/wpt/tests/dom/observable/tentative/observable-takeUntil.any.js
@@ -179,10 +179,10 @@ promise_test(async t => {
   assert_array_equals(results, [
     "notifier subscribed",
     "source subscribed",
-    "notifier teardown",
     "notifier signal abort",
-    "source teardown",
+    "notifier teardown",
     "source signal abort",
+    "source teardown",
     "complete callback",
   ]);
 }, "takeUntil: notifier next() unsubscribes from notifier & source observable");
@@ -235,10 +235,10 @@ promise_test(async t => {
   assert_array_equals(results, [
     "notifier subscribed",
     "source subscribed",
-    "notifier teardown",
     "notifier signal abort",
+    "notifier teardown",
+    "source signal abort",
     "source teardown",
-    "source signal abort"
   ]);
 }, "takeUntil()'s AbortSignal unsubscribes from notifier & source observable");
 
diff --git a/tests/wpt/tests/dom/observable/tentative/observable-toArray.any.js b/tests/wpt/tests/dom/observable/tentative/observable-toArray.any.js
index 9e6e3abee56..582bc67453e 100644
--- a/tests/wpt/tests/dom/observable/tentative/observable-toArray.any.js
+++ b/tests/wpt/tests/dom/observable/tentative/observable-toArray.any.js
@@ -152,9 +152,9 @@ promise_test(async () => {
 
   assert_array_equals(results, [
     "Subscribed. active: true",
-    "Outer signal abort event",
-    "Teardown",
     "Inner signal abort event",
+    "Teardown",
+    "Outer signal abort event",
   ], "Events and teardowns are fired in the right ordered");
 
   // Everything microtask above should be queued up by now, so queue one more
@@ -163,12 +163,12 @@ promise_test(async () => {
   await Promise.resolve();
   assert_array_equals(results, [
     "Subscribed. active: true",
-    "Outer signal abort event",
-    "Teardown",
     "Inner signal abort event",
-    "Outer signal Promise",
-    "Teardown Promise",
+    "Teardown",
+    "Outer signal abort event",
     "Inner signal Promise",
+    "Teardown Promise",
+    "Outer signal Promise",
   ], "Promises resolve in the right order");
 }, "Operator Promise abort ordering");
 
diff --git a/tests/wpt/tests/fedcm/META.yml b/tests/wpt/tests/fedcm/META.yml
new file mode 100644
index 00000000000..40b5b106f62
--- /dev/null
+++ b/tests/wpt/tests/fedcm/META.yml
@@ -0,0 +1,3 @@
+spec: https://fedidcg.github.io/FedCM/
+suggested_reviewers:
+  - npm
diff --git a/tests/wpt/tests/credential-management/fedcm-abort.https.html b/tests/wpt/tests/fedcm/fedcm-abort.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-abort.https.html
rename to tests/wpt/tests/fedcm/fedcm-abort.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-after-abort.https.html b/tests/wpt/tests/fedcm/fedcm-after-abort.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-after-abort.https.html
rename to tests/wpt/tests/fedcm/fedcm-after-abort.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-authz/fedcm-continue-on-disallowed.https.html b/tests/wpt/tests/fedcm/fedcm-authz/fedcm-continue-on-disallowed.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-authz/fedcm-continue-on-disallowed.https.html
rename to tests/wpt/tests/fedcm/fedcm-authz/fedcm-continue-on-disallowed.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-authz/fedcm-continue-on-with-account.https.html b/tests/wpt/tests/fedcm/fedcm-authz/fedcm-continue-on-with-account.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-authz/fedcm-continue-on-with-account.https.html
rename to tests/wpt/tests/fedcm/fedcm-authz/fedcm-continue-on-with-account.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-authz/fedcm-continue-on.https.html b/tests/wpt/tests/fedcm/fedcm-authz/fedcm-continue-on.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-authz/fedcm-continue-on.https.html
rename to tests/wpt/tests/fedcm/fedcm-authz/fedcm-continue-on.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-authz/fedcm-disclosure-text-shown.https.html b/tests/wpt/tests/fedcm/fedcm-authz/fedcm-disclosure-text-shown.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-authz/fedcm-disclosure-text-shown.https.html
rename to tests/wpt/tests/fedcm/fedcm-authz/fedcm-disclosure-text-shown.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-authz/fedcm-userinfo-after-resolve.https.html b/tests/wpt/tests/fedcm/fedcm-authz/fedcm-userinfo-after-resolve.https.html
similarity index 96%
rename from tests/wpt/tests/credential-management/fedcm-authz/fedcm-userinfo-after-resolve.https.html
rename to tests/wpt/tests/fedcm/fedcm-authz/fedcm-userinfo-after-resolve.https.html
index 0521f4a2ab5..e92f4898863 100644
--- a/tests/wpt/tests/credential-management/fedcm-authz/fedcm-userinfo-after-resolve.https.html
+++ b/tests/wpt/tests/fedcm/fedcm-authz/fedcm-userinfo-after-resolve.https.html
@@ -32,7 +32,7 @@ fedcm_test(async t => {
   assert_equals(cred.token, "account=1234");
 
   const iframe_in_idp_scope = `${alt_manifest_origin}/\
-credential-management/support/fedcm/userinfo-iframe.html`;
+fedcm/support/fedcm/userinfo-iframe.html`;
   const message = await createIframeWithPermissionPolicyAndWaitForMessage(t, iframe_in_idp_scope);
   assert_equals(message.result, "Pass");
   assert_equals(message.numAccounts, 1);
diff --git a/tests/wpt/tests/credential-management/fedcm-authz/resolve-after-preventsilentaccess.https.html b/tests/wpt/tests/fedcm/fedcm-authz/resolve-after-preventsilentaccess.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-authz/resolve-after-preventsilentaccess.https.html
rename to tests/wpt/tests/fedcm/fedcm-authz/resolve-after-preventsilentaccess.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-auto-reauthn-without-approved-clients.https.html b/tests/wpt/tests/fedcm/fedcm-auto-reauthn-without-approved-clients.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-auto-reauthn-without-approved-clients.https.html
rename to tests/wpt/tests/fedcm/fedcm-auto-reauthn-without-approved-clients.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-auto-selected-flag.https.html b/tests/wpt/tests/fedcm/fedcm-auto-selected-flag.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-auto-selected-flag.https.html
rename to tests/wpt/tests/fedcm/fedcm-auto-selected-flag.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-basic.https.html b/tests/wpt/tests/fedcm/fedcm-basic.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-basic.https.html
rename to tests/wpt/tests/fedcm/fedcm-basic.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-button-and-other-account/fedcm-button-mode-basics.tentative.https.html b/tests/wpt/tests/fedcm/fedcm-button-and-other-account/fedcm-button-mode-basics.tentative.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-button-and-other-account/fedcm-button-mode-basics.tentative.https.html
rename to tests/wpt/tests/fedcm/fedcm-button-and-other-account/fedcm-button-mode-basics.tentative.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-button-and-other-account/fedcm-button-mode-priority.tentative.https.html b/tests/wpt/tests/fedcm/fedcm-button-and-other-account/fedcm-button-mode-priority.tentative.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-button-and-other-account/fedcm-button-mode-priority.tentative.https.html
rename to tests/wpt/tests/fedcm/fedcm-button-and-other-account/fedcm-button-mode-priority.tentative.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-button-and-other-account/fedcm-use-other-account-button-flow.tentative.https.html b/tests/wpt/tests/fedcm/fedcm-button-and-other-account/fedcm-use-other-account-button-flow.tentative.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-button-and-other-account/fedcm-use-other-account-button-flow.tentative.https.html
rename to tests/wpt/tests/fedcm/fedcm-button-and-other-account/fedcm-use-other-account-button-flow.tentative.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-button-and-other-account/fedcm-use-other-account.tentative.https.html b/tests/wpt/tests/fedcm/fedcm-button-and-other-account/fedcm-use-other-account.tentative.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-button-and-other-account/fedcm-use-other-account.tentative.https.html
rename to tests/wpt/tests/fedcm/fedcm-button-and-other-account/fedcm-use-other-account.tentative.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-client-metadata-not-cached.https.html b/tests/wpt/tests/fedcm/fedcm-client-metadata-not-cached.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-client-metadata-not-cached.https.html
rename to tests/wpt/tests/fedcm/fedcm-client-metadata-not-cached.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-context.https.html b/tests/wpt/tests/fedcm/fedcm-context.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-context.https.html
rename to tests/wpt/tests/fedcm/fedcm-context.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-cross-origin-policy.https.html b/tests/wpt/tests/fedcm/fedcm-cross-origin-policy.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-cross-origin-policy.https.html
rename to tests/wpt/tests/fedcm/fedcm-cross-origin-policy.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-cross-origin-policy.https.html.sub.headers b/tests/wpt/tests/fedcm/fedcm-cross-origin-policy.https.html.sub.headers
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-cross-origin-policy.https.html.sub.headers
rename to tests/wpt/tests/fedcm/fedcm-cross-origin-policy.https.html.sub.headers
diff --git a/tests/wpt/tests/credential-management/fedcm-csp.https.html b/tests/wpt/tests/fedcm/fedcm-csp.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-csp.https.html
rename to tests/wpt/tests/fedcm/fedcm-csp.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-csp.https.html.sub.headers b/tests/wpt/tests/fedcm/fedcm-csp.https.html.sub.headers
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-csp.https.html.sub.headers
rename to tests/wpt/tests/fedcm/fedcm-csp.https.html.sub.headers
diff --git a/tests/wpt/tests/credential-management/fedcm-disconnect-errors.https.html b/tests/wpt/tests/fedcm/fedcm-disconnect-errors.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-disconnect-errors.https.html
rename to tests/wpt/tests/fedcm/fedcm-disconnect-errors.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-disconnect-iframe.sub.https.html b/tests/wpt/tests/fedcm/fedcm-disconnect-iframe.sub.https.html
similarity index 88%
rename from tests/wpt/tests/credential-management/fedcm-disconnect-iframe.sub.https.html
rename to tests/wpt/tests/fedcm/fedcm-disconnect-iframe.sub.https.html
index 3d31be60b18..275a4a55c5e 100644
--- a/tests/wpt/tests/credential-management/fedcm-disconnect-iframe.sub.https.html
+++ b/tests/wpt/tests/fedcm/fedcm-disconnect-iframe.sub.https.html
@@ -33,14 +33,14 @@ fedcm_test(async t => {
 
 fedcm_test(async t => {
   const message = await createIframeAndWaitForMessage(t,
-      'https://{{hosts[alt][]}}:{{ports[https][0]}}/credential-management/support/fedcm/disconnect-iframe.html?skip_get');
+      'https://{{hosts[alt][]}}:{{ports[https][0]}}/fedcm/support/fedcm/disconnect-iframe.html?skip_get');
   assert_equals(message.result, "Failed disconnect");
   assert_equals(message.errorType, "NotAllowedError");
 }, 'Cross-origin iframe fails disconnect() without explicit identity-credentials-get');
 
 fedcm_test(async t => {
   const message = await createIframeAndWaitForMessage(t,
-      'https://{{hosts[alt][]}}:{{ports[https][0]}}/credential-management/support/fedcm/disconnect-iframe.html',
+      'https://{{hosts[alt][]}}:{{ports[https][0]}}/fedcm/support/fedcm/disconnect-iframe.html',
       /*allow=*/true);
   assert_equals(message.result, "Pass");
 }, 'Cross-origin iframe can disconnect with explicit identity-credentials-get');
diff --git a/tests/wpt/tests/credential-management/fedcm-disconnect.sub.https.html b/tests/wpt/tests/fedcm/fedcm-disconnect.sub.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-disconnect.sub.https.html
rename to tests/wpt/tests/fedcm/fedcm-disconnect.sub.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-domainhint.https.html b/tests/wpt/tests/fedcm/fedcm-domainhint.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-domainhint.https.html
rename to tests/wpt/tests/fedcm/fedcm-domainhint.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-endpoint-redirects.https.html b/tests/wpt/tests/fedcm/fedcm-endpoint-redirects.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-endpoint-redirects.https.html
rename to tests/wpt/tests/fedcm/fedcm-endpoint-redirects.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-error-basic.https.html b/tests/wpt/tests/fedcm/fedcm-error-basic.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-error-basic.https.html
rename to tests/wpt/tests/fedcm/fedcm-error-basic.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-identity-assertion-nocors.https.html b/tests/wpt/tests/fedcm/fedcm-identity-assertion-nocors.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-identity-assertion-nocors.https.html
rename to tests/wpt/tests/fedcm/fedcm-identity-assertion-nocors.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-iframe.https.html b/tests/wpt/tests/fedcm/fedcm-iframe.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-iframe.https.html
rename to tests/wpt/tests/fedcm/fedcm-iframe.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-login-status-unknown.https.html b/tests/wpt/tests/fedcm/fedcm-login-status-unknown.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-login-status-unknown.https.html
rename to tests/wpt/tests/fedcm/fedcm-login-status-unknown.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-login-status/confirm-idp-login.https.html b/tests/wpt/tests/fedcm/fedcm-login-status/confirm-idp-login.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-login-status/confirm-idp-login.https.html
rename to tests/wpt/tests/fedcm/fedcm-login-status/confirm-idp-login.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-login-status/cross-origin-status.https.html b/tests/wpt/tests/fedcm/fedcm-login-status/cross-origin-status.https.html
similarity index 95%
rename from tests/wpt/tests/credential-management/fedcm-login-status/cross-origin-status.https.html
rename to tests/wpt/tests/fedcm/fedcm-login-status/cross-origin-status.https.html
index f32e18d40ed..dc0ff948904 100644
--- a/tests/wpt/tests/credential-management/fedcm-login-status/cross-origin-status.https.html
+++ b/tests/wpt/tests/fedcm/fedcm-login-status/cross-origin-status.https.html
@@ -18,7 +18,7 @@ import {fedcm_test,
         open_and_wait_for_popup,
         mark_signed_out} from '../support/fedcm-helper.sub.js';
 
-const path = '/credential-management/support/'
+const path = '/fedcm/support/'
 const url_prefix = alt_manifest_origin + path;
 const same_site_url_prefix = same_site_manifest_origin + path;
 
@@ -76,7 +76,7 @@ fedcm_test(async t => {
 
 fedcm_test(async t => {
   await mark_signed_out(alt_manifest_origin);
-  await open_and_wait_for_popup(alt_manifest_origin, "/credential-management/support/fencedframe-mark-signedin.html");
+  await open_and_wait_for_popup(alt_manifest_origin, "/fedcm/support/fencedframe-mark-signedin.html");
 
   const config = alt_request_options_with_mediation_required();
   const result = navigator.credentials.get(config);
diff --git a/tests/wpt/tests/credential-management/fedcm-login-status/logged-out.https.html b/tests/wpt/tests/fedcm/fedcm-login-status/logged-out.https.html
similarity index 96%
rename from tests/wpt/tests/credential-management/fedcm-login-status/logged-out.https.html
rename to tests/wpt/tests/fedcm/fedcm-login-status/logged-out.https.html
index 09750ff0968..4d11e64ff37 100644
--- a/tests/wpt/tests/credential-management/fedcm-login-status/logged-out.https.html
+++ b/tests/wpt/tests/fedcm/fedcm-login-status/logged-out.https.html
@@ -39,7 +39,7 @@ fedcm_test(async t => {
   await mark_signed_out(alt_manifest_origin);
 
   const iframe_in_idp_scope = `${alt_manifest_origin}/\
-credential-management/support/fedcm/userinfo-iframe.html`;
+fedcm/support/fedcm/userinfo-iframe.html`;
   const message = await createIframeWithPermissionPolicyAndWaitForMessage(t, iframe_in_idp_scope);
   assert_equals(message.result, "Fail");
 
diff --git a/tests/wpt/tests/credential-management/fedcm-loginhint.https.html b/tests/wpt/tests/fedcm/fedcm-loginhint.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-loginhint.https.html
rename to tests/wpt/tests/fedcm/fedcm-loginhint.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-manifest-not-in-list.https.html b/tests/wpt/tests/fedcm/fedcm-manifest-not-in-list.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-manifest-not-in-list.https.html
rename to tests/wpt/tests/fedcm/fedcm-manifest-not-in-list.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-multi-idp/fedcm-multi-idp-abort.https.html b/tests/wpt/tests/fedcm/fedcm-multi-idp/fedcm-multi-idp-abort.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-multi-idp/fedcm-multi-idp-abort.https.html
rename to tests/wpt/tests/fedcm/fedcm-multi-idp/fedcm-multi-idp-abort.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-multi-idp/fedcm-multi-idp-basic.https.html b/tests/wpt/tests/fedcm/fedcm-multi-idp/fedcm-multi-idp-basic.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-multi-idp/fedcm-multi-idp-basic.https.html
rename to tests/wpt/tests/fedcm/fedcm-multi-idp/fedcm-multi-idp-basic.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-multi-idp/fedcm-multi-idp-context.https.html b/tests/wpt/tests/fedcm/fedcm-multi-idp/fedcm-multi-idp-context.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-multi-idp/fedcm-multi-idp-context.https.html
rename to tests/wpt/tests/fedcm/fedcm-multi-idp/fedcm-multi-idp-context.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-multi-idp/fedcm-multi-idp-mediation-optional.https.html b/tests/wpt/tests/fedcm/fedcm-multi-idp/fedcm-multi-idp-mediation-optional.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-multi-idp/fedcm-multi-idp-mediation-optional.https.html
rename to tests/wpt/tests/fedcm/fedcm-multi-idp/fedcm-multi-idp-mediation-optional.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-multi-idp/fedcm-multi-idp-mediation-silent.https.html b/tests/wpt/tests/fedcm/fedcm-multi-idp/fedcm-multi-idp-mediation-silent.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-multi-idp/fedcm-multi-idp-mediation-silent.https.html
rename to tests/wpt/tests/fedcm/fedcm-multi-idp/fedcm-multi-idp-mediation-silent.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-no-login-url.https.html b/tests/wpt/tests/fedcm/fedcm-no-login-url.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-no-login-url.https.html
rename to tests/wpt/tests/fedcm/fedcm-no-login-url.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-nonce-is-optional.https.html b/tests/wpt/tests/fedcm/fedcm-nonce-is-optional.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-nonce-is-optional.https.html
rename to tests/wpt/tests/fedcm/fedcm-nonce-is-optional.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-not-observed-by-service-worker.https.html b/tests/wpt/tests/fedcm/fedcm-not-observed-by-service-worker.https.html
similarity index 97%
rename from tests/wpt/tests/credential-management/fedcm-not-observed-by-service-worker.https.html
rename to tests/wpt/tests/fedcm/fedcm-not-observed-by-service-worker.https.html
index 072d6696656..a6537add106 100644
--- a/tests/wpt/tests/credential-management/fedcm-not-observed-by-service-worker.https.html
+++ b/tests/wpt/tests/fedcm/fedcm-not-observed-by-service-worker.https.html
@@ -26,7 +26,7 @@ function loadUrlInIframe(url) {
 
 fedcm_test(async t => {
   const service_worker_url = 'support/fedcm/intercept_service_worker.js';
-  const sw_scope_url = '/credential-management/support/fedcm/';
+  const sw_scope_url = '/fedcm/support/fedcm/';
   // URL for querying number of page loads observed by service worker.
   const query_sw_intercepts_url = 'support/fedcm/query_service_worker_intercepts.html';
   const page_in_sw_scope_url = 'support/fedcm/simple.html';
diff --git a/tests/wpt/tests/credential-management/fedcm-opaque-rp-origin.https.html b/tests/wpt/tests/fedcm/fedcm-opaque-rp-origin.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-opaque-rp-origin.https.html
rename to tests/wpt/tests/fedcm/fedcm-opaque-rp-origin.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-opaque-rp-origin.https.html.headers b/tests/wpt/tests/fedcm/fedcm-opaque-rp-origin.https.html.headers
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-opaque-rp-origin.https.html.headers
rename to tests/wpt/tests/fedcm/fedcm-opaque-rp-origin.https.html.headers
diff --git a/tests/wpt/tests/credential-management/fedcm-pending-call-rejected.https.html b/tests/wpt/tests/fedcm/fedcm-pending-call-rejected.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-pending-call-rejected.https.html
rename to tests/wpt/tests/fedcm/fedcm-pending-call-rejected.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-pending-disconnect.https.html b/tests/wpt/tests/fedcm/fedcm-pending-disconnect.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-pending-disconnect.https.html
rename to tests/wpt/tests/fedcm/fedcm-pending-disconnect.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-pending-userinfo.https.html b/tests/wpt/tests/fedcm/fedcm-pending-userinfo.https.html
similarity index 95%
rename from tests/wpt/tests/credential-management/fedcm-pending-userinfo.https.html
rename to tests/wpt/tests/fedcm/fedcm-pending-userinfo.https.html
index 0ecae3e80a4..1c85d4dc57d 100644
--- a/tests/wpt/tests/credential-management/fedcm-pending-userinfo.https.html
+++ b/tests/wpt/tests/fedcm/fedcm-pending-userinfo.https.html
@@ -29,7 +29,7 @@ fedcm_test(async t => {
   assert_equals(cred.token, "token");
 
   const iframe_in_idp_scope = `${alt_manifest_origin}/\
-credential-management/support/fedcm/pending-userinfo-iframe.html`;
+fedcm/support/fedcm/pending-userinfo-iframe.html`;
   const message = await createIframeWithPermissionPolicyAndWaitForMessage(t, iframe_in_idp_scope);
   assert_equals(message, "Pass");
 }, 'Test basic User InFo API flow');
diff --git a/tests/wpt/tests/credential-management/fedcm-register/fedcm-no-registered-idps.https.html b/tests/wpt/tests/fedcm/fedcm-register/fedcm-no-registered-idps.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-register/fedcm-no-registered-idps.https.html
rename to tests/wpt/tests/fedcm/fedcm-register/fedcm-no-registered-idps.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-reject-invalid-responses.https.html b/tests/wpt/tests/fedcm/fedcm-reject-invalid-responses.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-reject-invalid-responses.https.html
rename to tests/wpt/tests/fedcm/fedcm-reject-invalid-responses.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-returning-account-auto-reauthn.https.html b/tests/wpt/tests/fedcm/fedcm-returning-account-auto-reauthn.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-returning-account-auto-reauthn.https.html
rename to tests/wpt/tests/fedcm/fedcm-returning-account-auto-reauthn.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-same-site-none/fedcm-same-site-none.https.html b/tests/wpt/tests/fedcm/fedcm-same-site-none/fedcm-same-site-none.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-same-site-none/fedcm-same-site-none.https.html
rename to tests/wpt/tests/fedcm/fedcm-same-site-none/fedcm-same-site-none.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-store.https.html b/tests/wpt/tests/fedcm/fedcm-store.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-store.https.html
rename to tests/wpt/tests/fedcm/fedcm-store.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-token-returned-with-http-error.https.html b/tests/wpt/tests/fedcm/fedcm-token-returned-with-http-error.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-token-returned-with-http-error.https.html
rename to tests/wpt/tests/fedcm/fedcm-token-returned-with-http-error.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-too-many-disconnect-calls.https.html b/tests/wpt/tests/fedcm/fedcm-too-many-disconnect-calls.https.html
similarity index 100%
rename from tests/wpt/tests/credential-management/fedcm-too-many-disconnect-calls.https.html
rename to tests/wpt/tests/fedcm/fedcm-too-many-disconnect-calls.https.html
diff --git a/tests/wpt/tests/credential-management/fedcm-userinfo.https.html b/tests/wpt/tests/fedcm/fedcm-userinfo.https.html
similarity index 96%
rename from tests/wpt/tests/credential-management/fedcm-userinfo.https.html
rename to tests/wpt/tests/fedcm/fedcm-userinfo.https.html
index d460d828452..9f7be9fbbf3 100644
--- a/tests/wpt/tests/credential-management/fedcm-userinfo.https.html
+++ b/tests/wpt/tests/fedcm/fedcm-userinfo.https.html
@@ -29,7 +29,7 @@ fedcm_test(async t => {
   assert_equals(cred.token, "token");
 
   const iframe_in_idp_scope = `${alt_manifest_origin}/\
-credential-management/support/fedcm/userinfo-iframe.html`;
+fedcm/support/fedcm/userinfo-iframe.html`;
   const message = await createIframeWithPermissionPolicyAndWaitForMessage(t, iframe_in_idp_scope);
   assert_equals(message.result, "Pass");
   assert_equals(message.numAccounts, 1);
@@ -54,7 +54,7 @@ fedcm_test(async t => {
 
   try {
    const manifest_path = `${alt_manifest_origin}/\
-credential-management/support/fedcm/manifest.py`;
+fedcm/support/fedcm/manifest.py`;
     const user_info = await IdentityProvider.getUserInfo({
       configURL: manifest_path,
       // Approved client
diff --git a/tests/wpt/tests/fedcm/support/README.md b/tests/wpt/tests/fedcm/support/README.md
new file mode 100644
index 00000000000..28a6d3453bd
--- /dev/null
+++ b/tests/wpt/tests/fedcm/support/README.md
@@ -0,0 +1,20 @@
+# FedCM Testing
+
+`fedcm-mojojs-helper.js` exposes `fedcm_mojo_mock_test` which is a specialized
+`promise_test` which comes pre-setup with the appropriate mocking infrastructure
+to emulate platform federated auth backend. The mock is passed to the test
+function as the second parameter.
+
+Example usage:
+```
+<script type="module">
+  import {fedcm_mojo_mock_test} from './support/fedcm-mojojs-helper.js';
+
+  fedcm_mojo_mock_test(async (t, mock) => {
+    mock.returnToken("https://idp.test/fedcm.json", "a_token");
+    assert_equals("a_token", await navigator.credentials.get(options));
+  }, "Successfully obtaining a token using mock.");
+</script>
+```
+
+The chromium implementation uses the MojoJS shim.
diff --git a/tests/wpt/tests/fedcm/support/accounts_check_same_site_strict.py b/tests/wpt/tests/fedcm/support/accounts_check_same_site_strict.py
index 27a5d6a5b3e..7bab26d3e9b 100644
--- a/tests/wpt/tests/fedcm/support/accounts_check_same_site_strict.py
+++ b/tests/wpt/tests/fedcm/support/accounts_check_same_site_strict.py
@@ -7,6 +7,7 @@ def main(request, response):
     return request_error
   if request.cookies.get(b"same_site_strict") == b"1":
     return (546, [], "Should not send SameSite=Strict cookies")
+  # TODO(crbug.com/350944661): We want to send these cookies.
   if request.cookies.get(b"same_site_lax") == b"1":
     return (547, [], "Should not send SameSite=Lax cookies")
   if request.headers.get(b"Sec-Fetch-Site") != b"cross-site":
diff --git a/tests/wpt/tests/credential-management/support/fedcm-helper.sub.js b/tests/wpt/tests/fedcm/support/fedcm-helper.sub.js
similarity index 96%
rename from tests/wpt/tests/credential-management/support/fedcm-helper.sub.js
rename to tests/wpt/tests/fedcm/support/fedcm-helper.sub.js
index 17ed5ce4468..767c044818e 100644
--- a/tests/wpt/tests/credential-management/support/fedcm-helper.sub.js
+++ b/tests/wpt/tests/fedcm/support/fedcm-helper.sub.js
@@ -25,11 +25,10 @@ export function open_and_wait_for_popup(origin, path) {
 // Set the identity provider cookie.
 export function set_fedcm_cookie(host) {
   if (host == undefined) {
-    document.cookie = 'cookie=1; SameSite=None; Path=/credential-management/support; Secure';
     document.cookie = 'cookie=1; SameSite=None; Path=/fedcm/support; Secure';
     return Promise.resolve();
   } else {
-    return open_and_wait_for_popup(host, '/credential-management/support/set_cookie');
+    return open_and_wait_for_popup(host, '/fedcm/support/set_cookie');
   }
 }
 
@@ -39,11 +38,11 @@ export function set_alt_fedcm_cookie() {
 }
 
 export function mark_signed_in(origin = manifest_origin) {
-  return open_and_wait_for_popup(origin, '/credential-management/support/mark_signedin');
+  return open_and_wait_for_popup(origin, '/fedcm/support/mark_signedin');
 }
 
 export function mark_signed_out(origin = manifest_origin) {
-  return open_and_wait_for_popup(origin, '/credential-management/support/mark_signedout');
+  return open_and_wait_for_popup(origin, '/fedcm/support/mark_signedout');
 }
 
 // Returns FedCM CredentialRequestOptions for which navigator.credentials.get()
diff --git a/tests/wpt/tests/credential-management/support/fedcm-helper.sub.js.headers b/tests/wpt/tests/fedcm/support/fedcm-helper.sub.js.headers
similarity index 100%
rename from tests/wpt/tests/credential-management/support/fedcm-helper.sub.js.headers
rename to tests/wpt/tests/fedcm/support/fedcm-helper.sub.js.headers
diff --git a/tests/wpt/tests/credential-management/support/fedcm-iframe-level2.html b/tests/wpt/tests/fedcm/support/fedcm-iframe-level2.html
similarity index 100%
rename from tests/wpt/tests/credential-management/support/fedcm-iframe-level2.html
rename to tests/wpt/tests/fedcm/support/fedcm-iframe-level2.html
diff --git a/tests/wpt/tests/credential-management/support/fedcm-iframe.html b/tests/wpt/tests/fedcm/support/fedcm-iframe.html
similarity index 100%
rename from tests/wpt/tests/credential-management/support/fedcm-iframe.html
rename to tests/wpt/tests/fedcm/support/fedcm-iframe.html
diff --git a/tests/wpt/tests/credential-management/support/fedcm-mock.js b/tests/wpt/tests/fedcm/support/fedcm-mock.js
similarity index 100%
rename from tests/wpt/tests/credential-management/support/fedcm-mock.js
rename to tests/wpt/tests/fedcm/support/fedcm-mock.js
diff --git a/tests/wpt/tests/credential-management/support/fedcm-mojojs-helper.js b/tests/wpt/tests/fedcm/support/fedcm-mojojs-helper.js
similarity index 100%
rename from tests/wpt/tests/credential-management/support/fedcm-mojojs-helper.js
rename to tests/wpt/tests/fedcm/support/fedcm-mojojs-helper.js
diff --git a/tests/wpt/tests/credential-management/support/fedcm/disconnect-iframe.html b/tests/wpt/tests/fedcm/support/fedcm/disconnect-iframe.html
similarity index 100%
rename from tests/wpt/tests/credential-management/support/fedcm/disconnect-iframe.html
rename to tests/wpt/tests/fedcm/support/fedcm/disconnect-iframe.html
diff --git a/tests/wpt/tests/credential-management/support/fedcm/intercept_service_worker.js b/tests/wpt/tests/fedcm/support/fedcm/intercept_service_worker.js
similarity index 69%
rename from tests/wpt/tests/credential-management/support/fedcm/intercept_service_worker.js
rename to tests/wpt/tests/fedcm/support/fedcm/intercept_service_worker.js
index fd0bb71a0c7..b458c973be3 100644
--- a/tests/wpt/tests/credential-management/support/fedcm/intercept_service_worker.js
+++ b/tests/wpt/tests/fedcm/support/fedcm/intercept_service_worker.js
@@ -4,8 +4,7 @@ self.addEventListener('fetch', event => {
   const url = event.request.url;
   if (url.indexOf('query_service_worker_intercepts.html') != -1) {
     event.respondWith(new Response(num_overridden));
-  } else if (url.indexOf('credential-management/support' ||
-             url.indexOf('fedcm/support') != -1)) {
+  } else if (url.indexOf('fedcm/support') != -1) {
     ++num_overridden;
   }
 });
diff --git a/tests/wpt/tests/credential-management/support/fedcm/pending-userinfo-iframe.html b/tests/wpt/tests/fedcm/support/fedcm/pending-userinfo-iframe.html
similarity index 100%
rename from tests/wpt/tests/credential-management/support/fedcm/pending-userinfo-iframe.html
rename to tests/wpt/tests/fedcm/support/fedcm/pending-userinfo-iframe.html
diff --git a/tests/wpt/tests/credential-management/support/fedcm/simple.html b/tests/wpt/tests/fedcm/support/fedcm/simple.html
similarity index 100%
rename from tests/wpt/tests/credential-management/support/fedcm/simple.html
rename to tests/wpt/tests/fedcm/support/fedcm/simple.html
diff --git a/tests/wpt/tests/credential-management/support/fedcm/userinfo-iframe.html b/tests/wpt/tests/fedcm/support/fedcm/userinfo-iframe.html
similarity index 100%
rename from tests/wpt/tests/credential-management/support/fedcm/userinfo-iframe.html
rename to tests/wpt/tests/fedcm/support/fedcm/userinfo-iframe.html
diff --git a/tests/wpt/tests/credential-management/support/fencedframe-mark-signedin.html b/tests/wpt/tests/fedcm/support/fencedframe-mark-signedin.html
similarity index 100%
rename from tests/wpt/tests/credential-management/support/fencedframe-mark-signedin.html
rename to tests/wpt/tests/fedcm/support/fencedframe-mark-signedin.html
diff --git a/tests/wpt/tests/credential-management/support/iframe-mark-signedin.html b/tests/wpt/tests/fedcm/support/iframe-mark-signedin.html
similarity index 100%
rename from tests/wpt/tests/credential-management/support/iframe-mark-signedin.html
rename to tests/wpt/tests/fedcm/support/iframe-mark-signedin.html
diff --git a/tests/wpt/tests/credential-management/support/mark_signedin b/tests/wpt/tests/fedcm/support/mark_signedin
similarity index 100%
rename from tests/wpt/tests/credential-management/support/mark_signedin
rename to tests/wpt/tests/fedcm/support/mark_signedin
diff --git a/tests/wpt/tests/credential-management/support/mark_signedin.sub.headers b/tests/wpt/tests/fedcm/support/mark_signedin.sub.headers
similarity index 100%
rename from tests/wpt/tests/credential-management/support/mark_signedin.sub.headers
rename to tests/wpt/tests/fedcm/support/mark_signedin.sub.headers
diff --git a/tests/wpt/tests/credential-management/support/mark_signedout b/tests/wpt/tests/fedcm/support/mark_signedout
similarity index 100%
rename from tests/wpt/tests/credential-management/support/mark_signedout
rename to tests/wpt/tests/fedcm/support/mark_signedout
diff --git a/tests/wpt/tests/credential-management/support/mark_signedout.sub.headers b/tests/wpt/tests/fedcm/support/mark_signedout.sub.headers
similarity index 100%
rename from tests/wpt/tests/credential-management/support/mark_signedout.sub.headers
rename to tests/wpt/tests/fedcm/support/mark_signedout.sub.headers
diff --git a/tests/wpt/tests/credential-management/support/set_cookie b/tests/wpt/tests/fedcm/support/set_cookie
similarity index 100%
rename from tests/wpt/tests/credential-management/support/set_cookie
rename to tests/wpt/tests/fedcm/support/set_cookie
diff --git a/tests/wpt/tests/credential-management/support/set_cookie.headers b/tests/wpt/tests/fedcm/support/set_cookie.headers
similarity index 100%
rename from tests/wpt/tests/credential-management/support/set_cookie.headers
rename to tests/wpt/tests/fedcm/support/set_cookie.headers
diff --git a/tests/wpt/tests/fedcm/support/token_check_same_site_strict.py b/tests/wpt/tests/fedcm/support/token_check_same_site_strict.py
index f030b9b6fd5..20bdc594877 100644
--- a/tests/wpt/tests/fedcm/support/token_check_same_site_strict.py
+++ b/tests/wpt/tests/fedcm/support/token_check_same_site_strict.py
@@ -7,6 +7,7 @@ def main(request, response):
     return request_error
   if request.cookies.get(b"same_site_strict") == b"1":
     return (546, [], "Should not send SameSite=Strict cookies")
+  # TODO(crbug.com/350944661): We want to send these cookies.
   if request.cookies.get(b"same_site_lax") == b"1":
     return (547, [], "Should not send SameSite=Lax cookies")
 
diff --git a/tests/wpt/tests/fetch/metadata/resources/post-to-owner.py b/tests/wpt/tests/fetch/metadata/resources/post-to-owner.py
index 256dd6e49dc..2d4896867bb 100644
--- a/tests/wpt/tests/fetch/metadata/resources/post-to-owner.py
+++ b/tests/wpt/tests/fetch/metadata/resources/post-to-owner.py
@@ -7,30 +7,20 @@ def main(request, response):
         (b"Content-Type", b"text/html"),
         (b"Cache-Control", b"no-cache, no-store, must-revalidate")
     ]
-    key = request.GET.first(b"key", None)
-
-    # We serialize the key into JSON, so have to decode it first.
-    if key is not None:
-      key = key.decode('utf-8')
 
     body = u"""
         <!DOCTYPE html>
-        <script src="/portals/resources/stash-utils.sub.js"></script>
         <script>
             var data = %s;
             if (window.opener)
                 window.opener.postMessage(data, "*");
             if (window.top != window)
                 window.top.postMessage(data, "*");
-
-            const key = %s;
-            if (key)
-                StashUtils.putValue(key, data);
         </script>
     """ % (json.dumps({
         u"dest": isomorphic_decode(request.headers.get(b"sec-fetch-dest", b"")),
         u"mode": isomorphic_decode(request.headers.get(b"sec-fetch-mode", b"")),
         u"site": isomorphic_decode(request.headers.get(b"sec-fetch-site", b"")),
         u"user": isomorphic_decode(request.headers.get(b"sec-fetch-user", b"")),
-        }), json.dumps(key))
+        }))
     return headers, body
diff --git a/tests/wpt/tests/geolocation/PositionOptions.https.html b/tests/wpt/tests/geolocation/PositionOptions.https.html
index e54e8679aa9..73d84738bd9 100644
--- a/tests/wpt/tests/geolocation/PositionOptions.https.html
+++ b/tests/wpt/tests/geolocation/PositionOptions.https.html
@@ -17,23 +17,6 @@
 
   const invalidValues = ["boom", 321, -Infinity, { foo: 5 }];
 
-  promise_test(async (t) => {
-    for (const enableHighAccuracy of invalidValues) {
-      navigator.geolocation.getCurrentPosition(() => {}, null, {
-        enableHighAccuracy,
-      });
-    }
-  }, "Call getCurrentPosition with wrong type for enableHighAccuracy. No exception expected.");
-
-  promise_test(async (t) => {
-    for (const enableHighAccuracy of invalidValues) {
-      const id = navigator.geolocation.watchPosition(() => {}, null, {
-        enableHighAccuracy,
-      });
-      navigator.geolocation.clearWatch(id);
-    }
-  }, "Call watchPosition with wrong type for enableHighAccuracy. No exception expected.");
-
   promise_test(async (t) => {
     const error = await new Promise((resolve, reject) => {
       navigator.geolocation.getCurrentPosition(reject, resolve, {
@@ -79,4 +62,22 @@
     assert_equals(error.code, GeolocationPositionError.TIMEOUT);
     navigator.geolocation.clearWatch(watchId);
   }, "Check that a negative timeout and maxAge values are clamped to 0 (watchPosition)");
+
+  promise_test(async (t) => {
+    for (const enableHighAccuracy of invalidValues) {
+      navigator.geolocation.getCurrentPosition(() => {}, null, {
+        enableHighAccuracy,
+      });
+    }
+  }, "Call getCurrentPosition with wrong type for enableHighAccuracy. No exception expected.");
+
+  promise_test(async (t) => {
+    for (const enableHighAccuracy of invalidValues) {
+      const id = navigator.geolocation.watchPosition(() => {}, null, {
+        enableHighAccuracy,
+      });
+      navigator.geolocation.clearWatch(id);
+    }
+  }, "Call watchPosition with wrong type for enableHighAccuracy. No exception expected.");
+
 </script>
diff --git a/tests/wpt/tests/geolocation/tojson.https.window.js b/tests/wpt/tests/geolocation/tojson.https.window.js
index f8cef07a7f0..b3f8500b1a8 100644
--- a/tests/wpt/tests/geolocation/tojson.https.window.js
+++ b/tests/wpt/tests/geolocation/tojson.https.window.js
@@ -1,51 +1,37 @@
 // META: script=/resources/testdriver.js
 // META: script=/resources/testdriver-vendor.js
-'use strict';
+"use strict";
 
-function check_coords(original, json, prefix) {
-  for (const key of [
-    'accuracy',
-    'latitude',
-    'longitude',
-    'altitude',
-    'altitudeAccuracy',
-    'heading',
-    'speed',
-    'coords',
-    'timestamp',
-  ]) {
-    assert_equals(original[key], json[key], `${prefix} ${key} entry does not match its toJSON value`);
+function check_equals(original, json) {
+  const proto = Object.getPrototypeOf(original);
+  const keys = Object.keys(proto).filter(
+    (k) => typeof original[k] !== "function",
+  );
+  for (const key of keys) {
+    assert_equals(
+      original[key],
+      json[key],
+      `${original.constructor.name} ${key} entry does not match its toJSON value`,
+    );
   }
 }
 
 promise_setup(async () => {
   await test_driver.set_permission({ name: "geolocation" }, "granted");
-
-  if (document.readyState != 'complete') {
-    await new Promise(resolve => {
-      window.addEventListener('load', resolve, {once: true});
-    });
-  }
-}, 'Grant permission and wait for the document to be fully active.');
+});
 
 promise_test(async (t) => {
   const position = await new Promise((resolve, reject) => {
-    navigator.geolocation.getCurrentPosition(
-      t.step_func((position) => {
-        resolve(position);
-      }),
-      t.step_func((error) => {
-        reject(error.message);
-      }),
-    );
+    navigator.geolocation.getCurrentPosition(resolve, reject);
   });
 
-  assert_equals(typeof(position.toJSON), 'function');
-
   const json = position.toJSON();
-  assert_equals(position.timestamp, json.timestamp, 'GeolocationPosition timestamp entry does not match its toJSON value');
-  check_coords(position.coords, json.coords, 'GeolocationPosition coords');
+  assert_equals(
+    position.timestamp,
+    json.timestamp,
+    "GeolocationPosition timestamp entry does not match its toJSON value",
+  );
 
-  assert_equals(typeof(position.coords.toJSON), 'function');
-  check_coords(position.coords, position.coords.toJSON(), 'GeolocationCoordinates');
-}, 'Test toJSON() in GeolocationPosition and GeolocationCoordinates.');
+  check_equals(position.coords, json.coords);
+  check_equals(position.coords, position.coords.toJSON());
+}, "Test toJSON() in GeolocationPosition and GeolocationCoordinates.");
diff --git a/tests/wpt/tests/hr-time/raf-coarsened-time.https.html b/tests/wpt/tests/hr-time/raf-coarsened-time.https.html
index e649d91c163..182c707dc3b 100644
--- a/tests/wpt/tests/hr-time/raf-coarsened-time.https.html
+++ b/tests/wpt/tests/hr-time/raf-coarsened-time.https.html
@@ -11,7 +11,7 @@
     const COARSE_RESOLUTION = 0.005;
 
     const CUSTOM_TIMELINE_DELTA = 0.002;
-    const FLOATING_POINT_ERROR_EPSILON = 0.00001;
+    const FLOATING_POINT_ERROR_EPSILON = 0.01;
 
     // Note that this test would fail if the platform introduces a jitter.
     // It is recommended that platforms that implement jitter run this test
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/first-party-to-first-party-cross-partition.sub.html b/tests/wpt/tests/html/browsers/windows/post-message/first-party-to-first-party-cross-partition.sub.html
deleted file mode 100644
index f91d9403ea0..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/first-party-to-first-party-cross-partition.sub.html
+++ /dev/null
@@ -1,26 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<title>postMessage: First-Party to First-Party, Cross-Partition</title>
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<body>
-<script>
-// Here's the set-up for this test:
-// Step 1. (Site 1 Window) set up listener and open Site 2 Window.
-// Step 2. (Site 2 Window) send "Site 2 Window" message to Site 1 Window.
-// Step 3. (Site 1 Window) receive "Site 2 Window" message and exit.
-
-async_test(t => {
-  // Step 3
-  const listener = t.step_func(e => {
-    if (e.data === "Site 2 Window") {
-      t.done();
-    }
-  });
-  // Step 1
-  window.addEventListener("message", listener);
-  const site2Window = window.open("http://{{hosts[alt][]}}:{{ports[http][0]}}/html/browsers/windows/post-message/resources/first-party-to-first-party-cross-partition-window.html", "", "noopener=false");
-  t.add_cleanup(() => site2Window.close());
-}, "postMessage: First-Party to First-Party, Cross-Partition");
-</script>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/first-party-to-first-party-same-partition.html b/tests/wpt/tests/html/browsers/windows/post-message/first-party-to-first-party-same-partition.html
deleted file mode 100644
index 6fc915298bb..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/first-party-to-first-party-same-partition.html
+++ /dev/null
@@ -1,26 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<title>postMessage: First-Party to First-Party, Same-Partition</title>
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<body>
-<script>
-// Here's the set-up for this test:
-// Step 1. (Site 1 Window A) set up listener and open Site 1 Window B.
-// Step 2. (Site 1 Window B) send "Site 1 Window B" message to Site 1 Window A.
-// Step 3. (Site 1 Window A) receive "Site 1 Window B" message and exit.
-
-async_test(t => {
-  // Step 3
-  const listener = t.step_func(e => {
-    if (e.data === "Site 1 Window B") {
-      t.done();
-    }
-  });
-  // Step 1
-  window.addEventListener("message", listener);
-  const site1WindowB = window.open("/html/browsers/windows/post-message/resources/first-party-to-first-party-same-partition-window.html", "", "noopener=false");
-  t.add_cleanup(() => site1WindowB.close());
-}, "postMessage: First-Party to First-Party, Same-Partition");
-</script>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/first-party-to-third-party-cross-partition-cross-origin.sub.html b/tests/wpt/tests/html/browsers/windows/post-message/first-party-to-third-party-cross-partition-cross-origin.sub.html
deleted file mode 100644
index de776f83818..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/first-party-to-third-party-cross-partition-cross-origin.sub.html
+++ /dev/null
@@ -1,27 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<title>postMessage: First-Party to Third-Party, Cross-Partition, Cross-Origin</title>
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<body>
-<script>
-// Here's the set-up for this test:
-// Step 1. (Site 1 Window) set up listener and open Site 2 Window.
-// Step 2. (Site 2 Window) open Site 3 Frame.
-// Step 3. (Site 3 Frame) send "Site 3 Frame" message to Site 1 Window.
-// Step 4. (Site 1 Window) receive "Site 1 Frame" message and exit.
-
-async_test(t => {
-  // Step 4
-  const listener = t.step_func(e => {
-    if (e.data === "Site 3 Frame") {
-      t.done();
-    }
-  });
-  // Step 1
-  window.addEventListener("message", listener);
-  const site2Window = window.open("https://{{hosts[alt][]}}:{{ports[https][0]}}/html/browsers/windows/post-message/resources/first-party-to-third-party-cross-partition-cross-origin-window.sub.https.html", "", "noopener=false");
-  t.add_cleanup(() => site2Window.close());
-}, "postMessage: First-Party to Third-Party, Cross-Partition, Cross-Origin");
-</script>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/first-party-to-third-party-cross-partition-same-origin.sub.html b/tests/wpt/tests/html/browsers/windows/post-message/first-party-to-third-party-cross-partition-same-origin.sub.html
deleted file mode 100644
index 490b647fa4a..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/first-party-to-third-party-cross-partition-same-origin.sub.html
+++ /dev/null
@@ -1,27 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<title>postMessage: First-Party to Third-Party, Cross-Partition, Same-Origin</title>
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<body>
-<script>
-// Here's the set-up for this test:
-// Step 1. (Site 1 Window) set up listener and open Site 2 Window.
-// Step 2. (Site 2 Window) open Site 1 Frame.
-// Step 3. (Site 1 Frame) send "Site 1 Frame" message to Site 1 Window.
-// Step 4. (Site 1 Window) receive "Site 1 Frame" message and exit.
-
-async_test(t => {
-  // Step 4
-  const listener = t.step_func(e => {
-    if (e.data === "Site 1 Frame") {
-      t.done();
-    }
-  });
-  // Step 1
-  window.addEventListener("message", listener);
-  const site2Window = window.open("http://{{hosts[alt][]}}:{{ports[http][0]}}/html/browsers/windows/post-message/resources/first-party-to-third-party-cross-partition-same-origin-window.sub.html", "", "noopener=false");
-  t.add_cleanup(() => site2Window.close());
-}, "postMessage: First-Party to Third-Party, Cross-Partition, Same-Origin");
-</script>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/resources/first-party-to-first-party-cross-partition-window.html b/tests/wpt/tests/html/browsers/windows/post-message/resources/first-party-to-first-party-cross-partition-window.html
deleted file mode 100644
index cdfa9d95caa..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/resources/first-party-to-first-party-cross-partition-window.html
+++ /dev/null
@@ -1,8 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<body>
-<script>
-// Step 2 (html/browsers/windows/post-message/first-party-to-first-party-cross-partition.sub.html)
-window.opener.postMessage("Site 2 Window", "*");
-</script>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/resources/first-party-to-first-party-same-partition-window.html b/tests/wpt/tests/html/browsers/windows/post-message/resources/first-party-to-first-party-same-partition-window.html
deleted file mode 100644
index 4baf45d3c82..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/resources/first-party-to-first-party-same-partition-window.html
+++ /dev/null
@@ -1,8 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<body>
-<script>
-// Step 2 (html/browsers/windows/post-message/first-party-to-first-party-same-partition.html)
-window.opener.postMessage("Site 1 Window B", window.opener.origin);
-</script>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/resources/first-party-to-third-party-cross-partition-cross-origin-iframe.https.html b/tests/wpt/tests/html/browsers/windows/post-message/resources/first-party-to-third-party-cross-partition-cross-origin-iframe.https.html
deleted file mode 100644
index eef594831aa..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/resources/first-party-to-third-party-cross-partition-cross-origin-iframe.https.html
+++ /dev/null
@@ -1,8 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<body>
-<script>
-// Step 3 (html/browsers/windows/post-message/first-party-to-third-party-cross-partition-cross-origin.sub.html)
-window.top.opener.postMessage("Site 3 Frame", "*");
-</script>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/resources/first-party-to-third-party-cross-partition-cross-origin-window.sub.https.html b/tests/wpt/tests/html/browsers/windows/post-message/resources/first-party-to-third-party-cross-partition-cross-origin-window.sub.https.html
deleted file mode 100644
index 7edfbd93281..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/resources/first-party-to-third-party-cross-partition-cross-origin-window.sub.https.html
+++ /dev/null
@@ -1,6 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<body>
-<!--Step 2 (html/browsers/windows/post-message/first-party-to-third-party-cross-partition-cross-origin.sub.html)-->
-<iframe src="https://{{host}}:{{ports[https][0]}}/html/browsers/windows/post-message/resources/first-party-to-third-party-cross-partition-cross-origin-iframe.https.html"></iframe>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/resources/first-party-to-third-party-cross-partition-same-origin-iframe.html b/tests/wpt/tests/html/browsers/windows/post-message/resources/first-party-to-third-party-cross-partition-same-origin-iframe.html
deleted file mode 100644
index eb17036c8cc..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/resources/first-party-to-third-party-cross-partition-same-origin-iframe.html
+++ /dev/null
@@ -1,8 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<body>
-<script>
-// Step 3 (html/browsers/windows/post-message/first-party-to-third-party-cross-partition-same-origin.sub.html)
-window.top.opener.postMessage("Site 1 Frame", window.top.opener.origin);
-</script>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/resources/first-party-to-third-party-cross-partition-same-origin-window.sub.html b/tests/wpt/tests/html/browsers/windows/post-message/resources/first-party-to-third-party-cross-partition-same-origin-window.sub.html
deleted file mode 100644
index f99b96c4667..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/resources/first-party-to-third-party-cross-partition-same-origin-window.sub.html
+++ /dev/null
@@ -1,6 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<body>
-<!--Step 2 (html/browsers/windows/post-message/first-party-to-third-party-cross-partition-same-origin.sub.html)-->
-<iframe src="http://{{host}}:{{ports[http][0]}}/html/browsers/windows/post-message/resources/first-party-to-third-party-cross-partition-same-origin-iframe.html"></iframe>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-first-party-cross-partition-cross-origin-iframe.sub.html b/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-first-party-cross-partition-cross-origin-iframe.sub.html
deleted file mode 100644
index 348efb3f9c4..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-first-party-cross-partition-cross-origin-iframe.sub.html
+++ /dev/null
@@ -1,17 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<body>
-<script>
-// Step 4 (html/browsers/windows/post-message/third-party-to-first-party-cross-partition-cross-origin.sub.html)
-let site2Window;
-const listener = e => {
-  if (e.data === "Site 3 Window") {
-    site2Window.close();
-    window.top.postMessage("Site 2 Frame", "*");
-  }
-};
-// Step 2 (html/browsers/windows/post-message/third-party-to-first-party-cross-partition-cross-origin.sub.html)
-window.addEventListener("message", listener);
-site2Window = window.open("https://{{hosts[alt][]}}:{{ports[https][0]}}/html/browsers/windows/post-message/resources/third-party-to-first-party-cross-partition-cross-origin-window.https.html", "", "noopener=false");
-</script>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-first-party-cross-partition-cross-origin-window.https.html b/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-first-party-cross-partition-cross-origin-window.https.html
deleted file mode 100644
index 00459094941..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-first-party-cross-partition-cross-origin-window.https.html
+++ /dev/null
@@ -1,8 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<body>
-<script>
-// Step 3 (html/browsers/windows/post-message/third-party-to-first-party-cross-partition-cross-origin.sub.html)
-window.opener.postMessage("Site 3 Window", "*");
-</script>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-first-party-cross-partition-same-origin-iframe.sub.html b/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-first-party-cross-partition-same-origin-iframe.sub.html
deleted file mode 100644
index 405b1053d33..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-first-party-cross-partition-same-origin-iframe.sub.html
+++ /dev/null
@@ -1,17 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<body>
-<script>
-// Step 4 (html/browsers/windows/post-message/third-party-to-first-party-cross-partition-same-origin.sub.html)
-let site2Window;
-const listener = e => {
-  if (e.data === "Site 2 Window") {
-    site2Window.close();
-    window.top.postMessage("Site 2 Frame", "*");
-  }
-};
-// Step 2 (html/browsers/windows/post-message/third-party-to-first-party-cross-partition-same-origin.sub.html)
-window.addEventListener("message", listener);
-site2Window = window.open("http://{{hosts[alt][]}}:{{ports[http][0]}}/html/browsers/windows/post-message/resources/third-party-to-first-party-cross-partition-same-origin-window.html", "", "noopener=false");
-</script>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-first-party-cross-partition-same-origin-window.html b/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-first-party-cross-partition-same-origin-window.html
deleted file mode 100644
index 0ae51e3fc17..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-first-party-cross-partition-same-origin-window.html
+++ /dev/null
@@ -1,8 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<body>
-<script>
-// Step 3 (html/browsers/windows/post-message/third-party-to-first-party-cross-partition-same-origin.sub.html)
-window.opener.postMessage("Site 2 Window", window.opener.origin);
-</script>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-cross-origin-iframe-a.sub.html b/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-cross-origin-iframe-a.sub.html
deleted file mode 100644
index a11f3640e83..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-cross-origin-iframe-a.sub.html
+++ /dev/null
@@ -1,17 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<body>
-<script>
-// Step 5 (html/browsers/windows/post-message/third-party-to-third-party-cross-partition-cross-origin.sub.html)
-let site3Window;
-const listener = e => {
-  if (e.data === "Site 4 Frame") {
-    site3Window.close();
-    window.top.postMessage("Site 2 Frame", "*");
-  }
-};
-// Step 2 (html/browsers/windows/post-message/third-party-to-third-party-cross-partition-cross-origin.sub.html)
-window.addEventListener("message", listener);
-site3Window = window.open("https://{{host}}:{{ports[https][0]}}/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-cross-origin-window.sub.https.html", "", "noopener=false");
-</script>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-cross-origin-iframe-b.https.html b/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-cross-origin-iframe-b.https.html
deleted file mode 100644
index f56e2b35d8b..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-cross-origin-iframe-b.https.html
+++ /dev/null
@@ -1,8 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<body>
-<script>
-// Step 4 (html/browsers/windows/post-message/third-party-to-third-party-cross-partition-cross-origin.sub.html)
-window.top.opener.postMessage("Site 4 Frame", "*");
-</script>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-cross-origin-window.sub.https.html b/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-cross-origin-window.sub.https.html
deleted file mode 100644
index 13072875879..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-cross-origin-window.sub.https.html
+++ /dev/null
@@ -1,6 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<body>
-<!--Step 3 (html/browsers/windows/post-message/third-party-to-third-party-cross-partition-cross-origin.sub.html)-->
-<iframe src="https://{{hosts[alt][]}}:{{ports[https][0]}}/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-cross-origin-iframe-b.https.html"></iframe>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-same-origin-iframe-a.sub.https.html b/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-same-origin-iframe-a.sub.https.html
deleted file mode 100644
index ec551bfdec9..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-same-origin-iframe-a.sub.https.html
+++ /dev/null
@@ -1,17 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<body>
-<script>
-// Step 5 (html/browsers/windows/post-message/third-party-to-third-party-cross-partition-same-origin.sub.html)
-let site3Window;
-const listener = e => {
-  if (e.data === "Site 2 Frame B") {
-    site3Window.close();
-    window.top.postMessage("Site 2 Frame A", "*");
-  }
-};
-// Step 2 (html/browsers/windows/post-message/third-party-to-third-party-cross-partition-same-origin.sub.html)
-window.addEventListener("message", listener);
-site3Window = window.open("https://{{host}}:{{ports[https][0]}}/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-same-origin-window.sub.https.html", "", "noopener=false");
-</script>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-same-origin-iframe-b.https.html b/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-same-origin-iframe-b.https.html
deleted file mode 100644
index fc15b1f1252..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-same-origin-iframe-b.https.html
+++ /dev/null
@@ -1,8 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<body>
-<script>
-// Step 4 (html/browsers/windows/post-message/third-party-to-third-party-cross-partition-same-origin.sub.html)
-window.top.opener.postMessage("Site 2 Frame B", window.top.opener.origin);
-</script>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-same-origin-window.sub.https.html b/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-same-origin-window.sub.https.html
deleted file mode 100644
index f26f709db34..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-same-origin-window.sub.https.html
+++ /dev/null
@@ -1,6 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<body>
-<!--Step 3 (html/browsers/windows/post-message/third-party-to-third-party-cross-partition-same-origin.sub.html)-->
-<iframe src="https://{{hosts[alt][]}}:{{ports[https][0]}}/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-same-origin-iframe-b.https.html"></iframe>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-same-partition-iframe-a.sub.html b/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-same-partition-iframe-a.sub.html
deleted file mode 100644
index 339dc9f06eb..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-same-partition-iframe-a.sub.html
+++ /dev/null
@@ -1,17 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<body>
-<script>
-// Step 5 (html/browsers/windows/post-message/third-party-to-third-party-same-partition.sub.html)
-let site2WindowB;
-const listener = e => {
-  if (e.data === "Site 2 Frame B") {
-    site2WindowB.close();
-    window.top.postMessage("Site 2 Frame A", "*");
-  }
-};
-// Step 2 (html/browsers/windows/post-message/third-party-to-third-party-same-partition.sub.html)
-window.addEventListener("message", listener);
-site2WindowB = window.open("http://{{host}}:{{ports[http][0]}}/html/browsers/windows/post-message/resources/third-party-to-third-party-same-partition-window.sub.html", "", "noopener=false");
-</script>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-same-partition-iframe-b.html b/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-same-partition-iframe-b.html
deleted file mode 100644
index daaf236bfca..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-same-partition-iframe-b.html
+++ /dev/null
@@ -1,8 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<body>
-<script>
-// Step 4 (html/browsers/windows/post-message/third-party-to-third-party-same-partition.sub.html)
-window.top.opener.postMessage("Site 2 Frame B", window.top.opener.origin);
-</script>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-same-partition-window.sub.html b/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-same-partition-window.sub.html
deleted file mode 100644
index 7cea58f235c..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/resources/third-party-to-third-party-same-partition-window.sub.html
+++ /dev/null
@@ -1,6 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<body>
-<!--Step 3 (html/browsers/windows/post-message/third-party-to-third-party-same-partition.sub.html)-->
-<iframe src="http://{{hosts[alt][]}}:{{ports[http][0]}}/html/browsers/windows/post-message/resources/third-party-to-third-party-same-partition-iframe-b.html"></iframe>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/third-party-to-first-party-cross-partition-cross-origin.sub.html b/tests/wpt/tests/html/browsers/windows/post-message/third-party-to-first-party-cross-partition-cross-origin.sub.html
deleted file mode 100644
index 2618e966de6..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/third-party-to-first-party-cross-partition-cross-origin.sub.html
+++ /dev/null
@@ -1,29 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<title>postMessage: Third-Party to First-Party, Cross-Partition, Cross-Origin</title>
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<body>
-<script>
-// Here's the set-up for this test:
-// Step 1. (Site 1 Window) set up listener and open Site 2 Frame.
-// Step 2. (Site 2 Frame) set up listener and open Site 3 Window.
-// Step 3. (Site 3 Window) send "Site 3 Window" message to Site 2 Frame.
-// Step 4. (Site 2 Frame) receive "Site 3 Window" message and send "Site 2 Frame" message to Site 1 Window.
-// Step 5. (Site 1 Window) receive "Site 2 Frame" message and exit.
-
-async_test(t => {
-  // Step 5
-  const listener = t.step_func(e => {
-    if (e.data === "Site 2 Frame") {
-      t.done();
-    }
-  });
-  // Step 1
-  window.addEventListener("message", listener);
-  const site2Frame = document.createElement("iframe");
-  site2Frame.src = "http://{{hosts[alt][]}}:{{ports[http][0]}}/html/browsers/windows/post-message/resources/third-party-to-first-party-cross-partition-cross-origin-iframe.sub.html";
-  document.body.appendChild(site2Frame);
-}, "postMessage: Third-Party to First-Party, Cross-Partition, Cross-Origin");
-</script>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/third-party-to-first-party-cross-partition-same-origin.sub.html b/tests/wpt/tests/html/browsers/windows/post-message/third-party-to-first-party-cross-partition-same-origin.sub.html
deleted file mode 100644
index 735b4588411..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/third-party-to-first-party-cross-partition-same-origin.sub.html
+++ /dev/null
@@ -1,29 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<title>postMessage: Third-Party to First-Party, Cross-Partition, Same-Origin</title>
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<body>
-<script>
-// Here's the set-up for this test:
-// Step 1. (Site 1 Window) set up listener and open Site 2 Frame.
-// Step 2. (Site 2 Frame) set up listener and open Site 2 Window.
-// Step 3. (Site 2 Window) send "Site 2 Window" message to Site 2 Frame.
-// Step 4. (Site 2 Frame) receive "Site 2 Window" message and send "Site 2 Frame" message to Site 1 Window.
-// Step 5. (Site 1 Window) receive "Site 2 Frame" message and exit.
-
-async_test(t => {
-  // Step 5
-  const listener = t.step_func(e => {
-    if (e.data === "Site 2 Frame") {
-      t.done();
-    }
-  });
-  // Step 1
-  window.addEventListener("message", listener);
-  const site2Frame = document.createElement("iframe");
-  site2Frame.src = "http://{{hosts[alt][]}}:{{ports[http][0]}}/html/browsers/windows/post-message/resources/third-party-to-first-party-cross-partition-same-origin-iframe.sub.html";
-  document.body.appendChild(site2Frame);
-}, "postMessage: Third-Party to First-Party, Cross-Partition, Same-Origin");
-</script>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/third-party-to-third-party-cross-partition-cross-origin.sub.html b/tests/wpt/tests/html/browsers/windows/post-message/third-party-to-third-party-cross-partition-cross-origin.sub.html
deleted file mode 100644
index 1083071f7d2..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/third-party-to-third-party-cross-partition-cross-origin.sub.html
+++ /dev/null
@@ -1,30 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<title>postMessage: Third-Party to Third-Party, Cross-Partition, Cross-Origin</title>
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<body>
-<script>
-// Here's the set-up for this test:
-// Step 1. (Site 1 Window) set up listener and open Site 2 Frame.
-// Step 2. (Site 2 Frame) set up listener and open Site 3 Window.
-// Step 3. (Site 3 Window) open Site 4 Frame.
-// Step 4. (Site 4 Frame) send "Site 4 Frame" message to Site 2 Frame.
-// Step 5. (Site 2 Frame) receive "Site 4 Frame" message and send "Site 2 Frame" message to Site 1 Window.
-// Step 6. (Site 1 Window) receive "Site 2 Frame" message and exit.
-
-async_test(t => {
-  // Step 6
-  const listener = t.step_func(e => {
-    if (e.data === "Site 2 Frame") {
-      t.done();
-    }
-  });
-  // Step 1
-  window.addEventListener("message", listener);
-  const site2FrameA = document.createElement("iframe");
-  site2FrameA.src = "http://{{hosts[alt][]}}:{{ports[http][0]}}/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-cross-origin-iframe-a.sub.html";
-  document.body.appendChild(site2FrameA);
-}, "postMessage: Third-Party to Third-Party, Cross-Partition, Cross-Origin");
-</script>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/third-party-to-third-party-cross-partition-same-origin.sub.html b/tests/wpt/tests/html/browsers/windows/post-message/third-party-to-third-party-cross-partition-same-origin.sub.html
deleted file mode 100644
index 9caf6c11e48..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/third-party-to-third-party-cross-partition-same-origin.sub.html
+++ /dev/null
@@ -1,30 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<title>postMessage: Third-Party to Third-Party, Cross-Partition, Same-Origin</title>
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<body>
-<script>
-// Here's the set-up for this test:
-// Step 1. (Site 1 Window) set up listener and open Site 2 Frame A.
-// Step 2. (Site 2 Frame A) set up listener and open Site 3 Window.
-// Step 3. (Site 3 Window) open Site 2 Frame B.
-// Step 4. (Site 2 Frame B) send "Site 2 Frame B" message to Site 2 Frame A.
-// Step 5. (Site 2 Frame A) receive "Site 2 Frame B" message and send "Site 2 Frame A" message to Site 1 Window.
-// Step 6. (Site 1 Window) receive "Site 2 Frame A" message and exit.
-
-async_test(t => {
-  // Step 6
-  const listener = t.step_func(e => {
-    if (e.data === "Site 2 Frame A") {
-      t.done();
-    }
-  });
-  // Step 1
-  window.addEventListener("message", listener);
-  const site2FrameA = document.createElement("iframe");
-  site2FrameA.src = "https://{{hosts[alt][]}}:{{ports[https][0]}}/html/browsers/windows/post-message/resources/third-party-to-third-party-cross-partition-same-origin-iframe-a.sub.https.html";
-  document.body.appendChild(site2FrameA);
-}, "postMessage: Third-Party to Third-Party, Cross-Partition, Same-Origin");
-</script>
-</body>
diff --git a/tests/wpt/tests/html/browsers/windows/post-message/third-party-to-third-party-same-partition.sub.html b/tests/wpt/tests/html/browsers/windows/post-message/third-party-to-third-party-same-partition.sub.html
deleted file mode 100644
index c90a0552684..00000000000
--- a/tests/wpt/tests/html/browsers/windows/post-message/third-party-to-third-party-same-partition.sub.html
+++ /dev/null
@@ -1,30 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<title>postMessage: Third-Party to Third-Party, Same-Partition</title>
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<body>
-<script>
-// Here's the set-up for this test:
-// Step 1. (Site 1 Window A) set up listener and open Site 2 Frame A.
-// Step 2. (Site 2 Frame A) set up listener and open Site 1 Window B.
-// Step 3. (Site 1 Window B) open Site 2 Frame B.
-// Step 4. (Site 2 Frame B) send "Site 2 Frame B" message to Site 2 Frame A.
-// Step 5. (Site 2 Frame A) receive "Site 2 Frame B" message and send "Site 2 Frame A" message to Site 1 Window A.
-// Step 6. (Site 1 Window A) receive "Site 2 Frame A" message and exit.
-
-async_test(t => {
-  // Step 6
-  const listener = t.step_func(e => {
-    if (e.data === "Site 2 Frame A") {
-      t.done();
-    }
-  });
-  // Step 1
-  window.addEventListener("message", listener);
-  const site2FrameA = document.createElement("iframe");
-  site2FrameA.src = "http://{{hosts[alt][]}}:{{ports[http][0]}}/html/browsers/windows/post-message/resources/third-party-to-third-party-same-partition-iframe-a.sub.html";
-  document.body.appendChild(site2FrameA);
-}, "postMessage: Third-Party to Third-Party, Same-Partition");
-</script>
-</body>
diff --git a/tests/wpt/tests/html/canvas/element/text/2d.text.measure.caret-position-edge-cases.tentative.html b/tests/wpt/tests/html/canvas/element/text/2d.text.measure.caret-position-edge-cases.tentative.html
new file mode 100644
index 00000000000..b1d4b873973
--- /dev/null
+++ b/tests/wpt/tests/html/canvas/element/text/2d.text.measure.caret-position-edge-cases.tentative.html
@@ -0,0 +1,58 @@
+<!DOCTYPE html>
+<!-- DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py. -->
+<title>Canvas test: 2d.text.measure.caret-position-edge-cases.tentative</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/html/canvas/resources/canvas-tests.js"></script>
+<link rel="stylesheet" href="/html/canvas/resources/canvas-tests.css">
+<style>
+@font-face {
+  font-family: CanvasTest;
+  src: url("/fonts/CanvasTest.ttf");
+}
+</style>
+<body class="show_output">
+
+<h1>2d.text.measure.caret-position-edge-cases.tentative</h1>
+<p class="desc">Test the edge cases for caretPositionFromPoint, where the point is at the edge of glyph and at the midpoint.</p>
+
+
+<span style="font-family: CanvasTest; position: absolute; visibility: hidden">A</span>
+<p class="output">Actual output:</p>
+<canvas id="c" class="output" width="100" height="50"><p class="fallback">FAIL (fallback content)</p></canvas>
+
+<ul id="d"></ul>
+<script>
+promise_test(async t => {
+
+  var canvas = document.getElementById('c');
+  var ctx = canvas.getContext('2d');
+
+  await document.fonts.ready;
+  ctx.font = '50px CanvasTest';
+  ctx.direction = 'ltr';
+  ctx.align = 'left'
+  ctx.baseline = 'alphabetic'
+  tm = ctx.measureText('A');
+  const a_width = tm.width;
+  tm = ctx.measureText('B');
+  const b_width = tm.width;
+  tm = ctx.measureText('C');
+  const c_width = tm.width;
+  const epsilon = 1.0e-4;
+
+  tm = ctx.measureText('ABC');
+  _assert(tm.caretPositionFromPoint(0) == 0, "tm.caretPositionFromPoint(0) == 0");
+  _assert(tm.caretPositionFromPoint(a_width / 2) == 0, "tm.caretPositionFromPoint(a_width / 2) == 0");
+  _assert(tm.caretPositionFromPoint(a_width / 2 + 1) == 1, "tm.caretPositionFromPoint(a_width / 2 + 1) == 1");
+  _assert(tm.caretPositionFromPoint(a_width) == 1, "tm.caretPositionFromPoint(a_width) == 1");
+  _assert(tm.caretPositionFromPoint(a_width + b_width / 2) == 1, "tm.caretPositionFromPoint(a_width + b_width / 2) == 1");
+  _assert(tm.caretPositionFromPoint(a_width + b_width / 2 + 1) == 2, "tm.caretPositionFromPoint(a_width + b_width / 2 + 1) == 2");
+  _assert(tm.caretPositionFromPoint(a_width + b_width) == 2, "tm.caretPositionFromPoint(a_width + b_width) == 2");
+  _assert(tm.caretPositionFromPoint(a_width + b_width + c_width / 2) == 2, "tm.caretPositionFromPoint(a_width + b_width + c_width / 2) == 2");
+  _assert(tm.caretPositionFromPoint(a_width + b_width + c_width / 2 + 1) == 3, "tm.caretPositionFromPoint(a_width + b_width + c_width / 2 + 1) == 3");
+  _assert(tm.caretPositionFromPoint(a_width + b_width + c_width) == 3, "tm.caretPositionFromPoint(a_width + b_width + c_width) == 3");
+
+}, "Test the edge cases for caretPositionFromPoint, where the point is at the edge of glyph and at the midpoint.");
+</script>
+
diff --git a/tests/wpt/tests/html/canvas/element/text/2d.text.measure.caret-position-edges.tentative.html b/tests/wpt/tests/html/canvas/element/text/2d.text.measure.caret-position-edges.tentative.html
new file mode 100644
index 00000000000..3a772bfd6cd
--- /dev/null
+++ b/tests/wpt/tests/html/canvas/element/text/2d.text.measure.caret-position-edges.tentative.html
@@ -0,0 +1,714 @@
+<!DOCTYPE html>
+<!-- DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py. -->
+<title>Canvas test: 2d.text.measure.caret-position-edges.tentative</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/html/canvas/resources/canvas-tests.js"></script>
+<link rel="stylesheet" href="/html/canvas/resources/canvas-tests.css">
+
+<h1>2d.text.measure.caret-position-edges.tentative</h1>
+
+<script>
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('left' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('ltr' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('left' == 'start' || 'left' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('left' == 'start' || 'left' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align left.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('left' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('rtl' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('left' == 'start' || 'left' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('left' == 'start' || 'left' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align left.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('center' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('ltr' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('center' == 'start' || 'center' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('center' == 'start' || 'center' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align center.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('center' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('rtl' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('center' == 'start' || 'center' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('center' == 'start' || 'center' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align center.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('right' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('ltr' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('right' == 'start' || 'right' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('right' == 'start' || 'right' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align right.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('right' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('rtl' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('right' == 'start' || 'right' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('right' == 'start' || 'right' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align right.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('start' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('ltr' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('start' == 'start' || 'start' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('start' == 'start' || 'start' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'start';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align start.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('start' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('rtl' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('start' == 'start' || 'start' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('start' == 'start' || 'start' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'start';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align start.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('end' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('ltr' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('end' == 'start' || 'end' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('end' == 'start' || 'end' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'end';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align end.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('end' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('rtl' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('end' == 'start' || 'end' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('end' == 'start' || 'end' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'end';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align end.");
+
+</script>
+</div>
diff --git a/tests/wpt/tests/html/canvas/element/text/2d.text.measure.caret-position.tentative.html b/tests/wpt/tests/html/canvas/element/text/2d.text.measure.caret-position.tentative.html
new file mode 100644
index 00000000000..53c91264d7c
--- /dev/null
+++ b/tests/wpt/tests/html/canvas/element/text/2d.text.measure.caret-position.tentative.html
@@ -0,0 +1,4074 @@
+<!DOCTYPE html>
+<!-- DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py. -->
+<title>Canvas test: 2d.text.measure.caret-position.tentative</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/html/canvas/resources/canvas-tests.js"></script>
+<link rel="stylesheet" href="/html/canvas/resources/canvas-tests.css">
+
+<h1>2d.text.measure.caret-position.tentative</h1>
+
+<script>
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('left' == 'center') {
+      offset -= width / 2;
+    } else if ('left' == 'right' ||
+             ('ltr' == 'ltr' && 'left' == 'end') ||
+             ('ltr' == 'rtl' && 'left' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('left' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('left' == 'right' ||
+             ('ltr' == 'ltr' && 'left' == 'end') ||
+             ('ltr' == 'rtl' && 'left' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 0px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('left' == 'center') {
+      offset -= width / 2;
+    } else if ('left' == 'right' ||
+             ('rtl' == 'ltr' && 'left' == 'end') ||
+             ('rtl' == 'rtl' && 'left' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('left' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('left' == 'right' ||
+             ('rtl' == 'ltr' && 'left' == 'end') ||
+             ('rtl' == 'rtl' && 'left' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 0px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('center' == 'center') {
+      offset -= width / 2;
+    } else if ('center' == 'right' ||
+             ('ltr' == 'ltr' && 'center' == 'end') ||
+             ('ltr' == 'rtl' && 'center' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('center' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('center' == 'right' ||
+             ('ltr' == 'ltr' && 'center' == 'end') ||
+             ('ltr' == 'rtl' && 'center' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 0px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('center' == 'center') {
+      offset -= width / 2;
+    } else if ('center' == 'right' ||
+             ('rtl' == 'ltr' && 'center' == 'end') ||
+             ('rtl' == 'rtl' && 'center' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('center' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('center' == 'right' ||
+             ('rtl' == 'ltr' && 'center' == 'end') ||
+             ('rtl' == 'rtl' && 'center' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 0px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('right' == 'center') {
+      offset -= width / 2;
+    } else if ('right' == 'right' ||
+             ('ltr' == 'ltr' && 'right' == 'end') ||
+             ('ltr' == 'rtl' && 'right' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('right' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('right' == 'right' ||
+             ('ltr' == 'ltr' && 'right' == 'end') ||
+             ('ltr' == 'rtl' && 'right' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 0px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('right' == 'center') {
+      offset -= width / 2;
+    } else if ('right' == 'right' ||
+             ('rtl' == 'ltr' && 'right' == 'end') ||
+             ('rtl' == 'rtl' && 'right' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('right' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('right' == 'right' ||
+             ('rtl' == 'ltr' && 'right' == 'end') ||
+             ('rtl' == 'rtl' && 'right' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 0px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('start' == 'center') {
+      offset -= width / 2;
+    } else if ('start' == 'right' ||
+             ('ltr' == 'ltr' && 'start' == 'end') ||
+             ('ltr' == 'rtl' && 'start' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('start' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('start' == 'right' ||
+             ('ltr' == 'ltr' && 'start' == 'end') ||
+             ('ltr' == 'rtl' && 'start' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'start';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 0px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('start' == 'center') {
+      offset -= width / 2;
+    } else if ('start' == 'right' ||
+             ('rtl' == 'ltr' && 'start' == 'end') ||
+             ('rtl' == 'rtl' && 'start' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('start' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('start' == 'right' ||
+             ('rtl' == 'ltr' && 'start' == 'end') ||
+             ('rtl' == 'rtl' && 'start' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'start';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 0px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('end' == 'center') {
+      offset -= width / 2;
+    } else if ('end' == 'right' ||
+             ('ltr' == 'ltr' && 'end' == 'end') ||
+             ('ltr' == 'rtl' && 'end' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('end' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('end' == 'right' ||
+             ('ltr' == 'ltr' && 'end' == 'end') ||
+             ('ltr' == 'rtl' && 'end' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'end';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 0px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('end' == 'center') {
+      offset -= width / 2;
+    } else if ('end' == 'right' ||
+             ('rtl' == 'ltr' && 'end' == 'end') ||
+             ('rtl' == 'rtl' && 'end' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('end' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('end' == 'right' ||
+             ('rtl' == 'ltr' && 'end' == 'end') ||
+             ('rtl' == 'rtl' && 'end' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'end';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 0px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('left' == 'center') {
+      offset -= width / 2;
+    } else if ('left' == 'right' ||
+             ('ltr' == 'ltr' && 'left' == 'end') ||
+             ('ltr' == 'rtl' && 'left' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('left' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('left' == 'right' ||
+             ('ltr' == 'ltr' && 'left' == 'end') ||
+             ('ltr' == 'rtl' && 'left' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 10px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('left' == 'center') {
+      offset -= width / 2;
+    } else if ('left' == 'right' ||
+             ('rtl' == 'ltr' && 'left' == 'end') ||
+             ('rtl' == 'rtl' && 'left' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('left' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('left' == 'right' ||
+             ('rtl' == 'ltr' && 'left' == 'end') ||
+             ('rtl' == 'rtl' && 'left' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 10px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('center' == 'center') {
+      offset -= width / 2;
+    } else if ('center' == 'right' ||
+             ('ltr' == 'ltr' && 'center' == 'end') ||
+             ('ltr' == 'rtl' && 'center' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('center' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('center' == 'right' ||
+             ('ltr' == 'ltr' && 'center' == 'end') ||
+             ('ltr' == 'rtl' && 'center' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 10px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('center' == 'center') {
+      offset -= width / 2;
+    } else if ('center' == 'right' ||
+             ('rtl' == 'ltr' && 'center' == 'end') ||
+             ('rtl' == 'rtl' && 'center' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('center' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('center' == 'right' ||
+             ('rtl' == 'ltr' && 'center' == 'end') ||
+             ('rtl' == 'rtl' && 'center' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 10px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('right' == 'center') {
+      offset -= width / 2;
+    } else if ('right' == 'right' ||
+             ('ltr' == 'ltr' && 'right' == 'end') ||
+             ('ltr' == 'rtl' && 'right' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('right' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('right' == 'right' ||
+             ('ltr' == 'ltr' && 'right' == 'end') ||
+             ('ltr' == 'rtl' && 'right' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 10px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('right' == 'center') {
+      offset -= width / 2;
+    } else if ('right' == 'right' ||
+             ('rtl' == 'ltr' && 'right' == 'end') ||
+             ('rtl' == 'rtl' && 'right' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('right' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('right' == 'right' ||
+             ('rtl' == 'ltr' && 'right' == 'end') ||
+             ('rtl' == 'rtl' && 'right' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 10px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('start' == 'center') {
+      offset -= width / 2;
+    } else if ('start' == 'right' ||
+             ('ltr' == 'ltr' && 'start' == 'end') ||
+             ('ltr' == 'rtl' && 'start' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('start' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('start' == 'right' ||
+             ('ltr' == 'ltr' && 'start' == 'end') ||
+             ('ltr' == 'rtl' && 'start' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'start';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 10px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('start' == 'center') {
+      offset -= width / 2;
+    } else if ('start' == 'right' ||
+             ('rtl' == 'ltr' && 'start' == 'end') ||
+             ('rtl' == 'rtl' && 'start' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('start' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('start' == 'right' ||
+             ('rtl' == 'ltr' && 'start' == 'end') ||
+             ('rtl' == 'rtl' && 'start' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'start';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 10px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('end' == 'center') {
+      offset -= width / 2;
+    } else if ('end' == 'right' ||
+             ('ltr' == 'ltr' && 'end' == 'end') ||
+             ('ltr' == 'rtl' && 'end' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('end' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('end' == 'right' ||
+             ('ltr' == 'ltr' && 'end' == 'end') ||
+             ('ltr' == 'rtl' && 'end' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'end';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 10px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('end' == 'center') {
+      offset -= width / 2;
+    } else if ('end' == 'right' ||
+             ('rtl' == 'ltr' && 'end' == 'end') ||
+             ('rtl' == 'rtl' && 'end' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('end' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('end' == 'right' ||
+             ('rtl' == 'ltr' && 'end' == 'end') ||
+             ('rtl' == 'rtl' && 'end' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'end';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 10px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('left' == 'center') {
+      offset -= width / 2;
+    } else if ('left' == 'right' ||
+             ('ltr' == 'ltr' && 'left' == 'end') ||
+             ('ltr' == 'rtl' && 'left' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('left' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('left' == 'right' ||
+             ('ltr' == 'ltr' && 'left' == 'end') ||
+             ('ltr' == 'rtl' && 'left' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 0px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('left' == 'center') {
+      offset -= width / 2;
+    } else if ('left' == 'right' ||
+             ('rtl' == 'ltr' && 'left' == 'end') ||
+             ('rtl' == 'rtl' && 'left' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('left' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('left' == 'right' ||
+             ('rtl' == 'ltr' && 'left' == 'end') ||
+             ('rtl' == 'rtl' && 'left' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 0px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('center' == 'center') {
+      offset -= width / 2;
+    } else if ('center' == 'right' ||
+             ('ltr' == 'ltr' && 'center' == 'end') ||
+             ('ltr' == 'rtl' && 'center' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('center' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('center' == 'right' ||
+             ('ltr' == 'ltr' && 'center' == 'end') ||
+             ('ltr' == 'rtl' && 'center' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 0px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('center' == 'center') {
+      offset -= width / 2;
+    } else if ('center' == 'right' ||
+             ('rtl' == 'ltr' && 'center' == 'end') ||
+             ('rtl' == 'rtl' && 'center' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('center' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('center' == 'right' ||
+             ('rtl' == 'ltr' && 'center' == 'end') ||
+             ('rtl' == 'rtl' && 'center' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 0px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('right' == 'center') {
+      offset -= width / 2;
+    } else if ('right' == 'right' ||
+             ('ltr' == 'ltr' && 'right' == 'end') ||
+             ('ltr' == 'rtl' && 'right' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('right' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('right' == 'right' ||
+             ('ltr' == 'ltr' && 'right' == 'end') ||
+             ('ltr' == 'rtl' && 'right' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 0px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('right' == 'center') {
+      offset -= width / 2;
+    } else if ('right' == 'right' ||
+             ('rtl' == 'ltr' && 'right' == 'end') ||
+             ('rtl' == 'rtl' && 'right' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('right' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('right' == 'right' ||
+             ('rtl' == 'ltr' && 'right' == 'end') ||
+             ('rtl' == 'rtl' && 'right' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 0px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('start' == 'center') {
+      offset -= width / 2;
+    } else if ('start' == 'right' ||
+             ('ltr' == 'ltr' && 'start' == 'end') ||
+             ('ltr' == 'rtl' && 'start' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('start' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('start' == 'right' ||
+             ('ltr' == 'ltr' && 'start' == 'end') ||
+             ('ltr' == 'rtl' && 'start' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'start';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 0px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('start' == 'center') {
+      offset -= width / 2;
+    } else if ('start' == 'right' ||
+             ('rtl' == 'ltr' && 'start' == 'end') ||
+             ('rtl' == 'rtl' && 'start' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('start' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('start' == 'right' ||
+             ('rtl' == 'ltr' && 'start' == 'end') ||
+             ('rtl' == 'rtl' && 'start' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'start';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 0px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('end' == 'center') {
+      offset -= width / 2;
+    } else if ('end' == 'right' ||
+             ('ltr' == 'ltr' && 'end' == 'end') ||
+             ('ltr' == 'rtl' && 'end' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('end' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('end' == 'right' ||
+             ('ltr' == 'ltr' && 'end' == 'end') ||
+             ('ltr' == 'rtl' && 'end' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'end';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 0px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('end' == 'center') {
+      offset -= width / 2;
+    } else if ('end' == 'right' ||
+             ('rtl' == 'ltr' && 'end' == 'end') ||
+             ('rtl' == 'rtl' && 'end' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('end' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('end' == 'right' ||
+             ('rtl' == 'ltr' && 'end' == 'end') ||
+             ('rtl' == 'rtl' && 'end' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'end';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 0px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('left' == 'center') {
+      offset -= width / 2;
+    } else if ('left' == 'right' ||
+             ('ltr' == 'ltr' && 'left' == 'end') ||
+             ('ltr' == 'rtl' && 'left' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('left' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('left' == 'right' ||
+             ('ltr' == 'ltr' && 'left' == 'end') ||
+             ('ltr' == 'rtl' && 'left' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 10px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('left' == 'center') {
+      offset -= width / 2;
+    } else if ('left' == 'right' ||
+             ('rtl' == 'ltr' && 'left' == 'end') ||
+             ('rtl' == 'rtl' && 'left' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('left' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('left' == 'right' ||
+             ('rtl' == 'ltr' && 'left' == 'end') ||
+             ('rtl' == 'rtl' && 'left' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 10px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('center' == 'center') {
+      offset -= width / 2;
+    } else if ('center' == 'right' ||
+             ('ltr' == 'ltr' && 'center' == 'end') ||
+             ('ltr' == 'rtl' && 'center' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('center' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('center' == 'right' ||
+             ('ltr' == 'ltr' && 'center' == 'end') ||
+             ('ltr' == 'rtl' && 'center' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 10px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('center' == 'center') {
+      offset -= width / 2;
+    } else if ('center' == 'right' ||
+             ('rtl' == 'ltr' && 'center' == 'end') ||
+             ('rtl' == 'rtl' && 'center' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('center' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('center' == 'right' ||
+             ('rtl' == 'ltr' && 'center' == 'end') ||
+             ('rtl' == 'rtl' && 'center' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 10px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('right' == 'center') {
+      offset -= width / 2;
+    } else if ('right' == 'right' ||
+             ('ltr' == 'ltr' && 'right' == 'end') ||
+             ('ltr' == 'rtl' && 'right' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('right' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('right' == 'right' ||
+             ('ltr' == 'ltr' && 'right' == 'end') ||
+             ('ltr' == 'rtl' && 'right' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 10px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('right' == 'center') {
+      offset -= width / 2;
+    } else if ('right' == 'right' ||
+             ('rtl' == 'ltr' && 'right' == 'end') ||
+             ('rtl' == 'rtl' && 'right' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('right' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('right' == 'right' ||
+             ('rtl' == 'ltr' && 'right' == 'end') ||
+             ('rtl' == 'rtl' && 'right' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 10px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('start' == 'center') {
+      offset -= width / 2;
+    } else if ('start' == 'right' ||
+             ('ltr' == 'ltr' && 'start' == 'end') ||
+             ('ltr' == 'rtl' && 'start' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('start' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('start' == 'right' ||
+             ('ltr' == 'ltr' && 'start' == 'end') ||
+             ('ltr' == 'rtl' && 'start' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'start';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 10px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('start' == 'center') {
+      offset -= width / 2;
+    } else if ('start' == 'right' ||
+             ('rtl' == 'ltr' && 'start' == 'end') ||
+             ('rtl' == 'rtl' && 'start' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('start' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('start' == 'right' ||
+             ('rtl' == 'ltr' && 'start' == 'end') ||
+             ('rtl' == 'rtl' && 'start' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'start';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 10px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('end' == 'center') {
+      offset -= width / 2;
+    } else if ('end' == 'right' ||
+             ('ltr' == 'ltr' && 'end' == 'end') ||
+             ('ltr' == 'rtl' && 'end' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('end' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('end' == 'right' ||
+             ('ltr' == 'ltr' && 'end' == 'end') ||
+             ('ltr' == 'rtl' && 'end' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'end';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 10px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('end' == 'center') {
+      offset -= width / 2;
+    } else if ('end' == 'right' ||
+             ('rtl' == 'ltr' && 'end' == 'end') ||
+             ('rtl' == 'rtl' && 'end' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('end' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('end' == 'right' ||
+             ('rtl' == 'ltr' && 'end' == 'end') ||
+             ('rtl' == 'rtl' && 'end' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'end';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 10px letter spacing and directional-override.");
+
+</script>
+</div>
diff --git a/tests/wpt/tests/html/canvas/element/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.html b/tests/wpt/tests/html/canvas/element/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.html
new file mode 100644
index 00000000000..8ce7ed79482
--- /dev/null
+++ b/tests/wpt/tests/html/canvas/element/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.html
@@ -0,0 +1,45 @@
+<!DOCTYPE html>
+<!-- DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py. -->
+<title>Canvas test: 2d.text.measure.getActualBoundingBox-exceptions.tentative</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/html/canvas/resources/canvas-tests.js"></script>
+<link rel="stylesheet" href="/html/canvas/resources/canvas-tests.css">
+<body class="show_output">
+
+<h1>2d.text.measure.getActualBoundingBox-exceptions.tentative</h1>
+<p class="desc">Check that TextMetrics::getActualBoundingBox() throws when using invalid indexes.</p>
+
+
+<p class="output">Actual output:</p>
+<canvas id="c" class="output" width="100" height="50"><p class="fallback">FAIL (fallback content)</p></canvas>
+
+<ul id="d"></ul>
+<script>
+var t = async_test("Check that TextMetrics::getActualBoundingBox() throws when using invalid indexes.");
+_addTest(function(canvas, ctx) {
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (const text of kTexts) {
+    const tm = ctx.measureText(text);
+    // Handled by the IDL binding.
+    assert_throws_js(TypeError, () => tm.getActualBoundingBox(-1, 0) );
+    assert_throws_js(TypeError, () => tm.getActualBoundingBox(0, -1) );
+    assert_throws_js(TypeError, () => tm.getActualBoundingBox(-1, -1) );
+    // Thrown in TextMetrics.
+    assert_throws_dom("IndexSizeError",
+                      () => tm.getActualBoundingBox(text.length, 0) );
+    assert_throws_dom("IndexSizeError",
+                      () => tm.getActualBoundingBox(0, text.length + 1) );
+    assert_throws_dom("IndexSizeError",
+                      () => tm.getActualBoundingBox(text.length, text.length + 1) );
+
+});
+</script>
+
diff --git a/tests/wpt/tests/html/canvas/element/text/2d.text.measure.getActualBoundingBox-full-text.tentative.html b/tests/wpt/tests/html/canvas/element/text/2d.text.measure.getActualBoundingBox-full-text.tentative.html
new file mode 100644
index 00000000000..510bce84f28
--- /dev/null
+++ b/tests/wpt/tests/html/canvas/element/text/2d.text.measure.getActualBoundingBox-full-text.tentative.html
@@ -0,0 +1,278 @@
+<!DOCTYPE html>
+<!-- DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py. -->
+<title>Canvas test: 2d.text.measure.getActualBoundingBox-full-text.tentative</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/html/canvas/resources/canvas-tests.js"></script>
+<link rel="stylesheet" href="/html/canvas/resources/canvas-tests.css">
+
+<h1>2d.text.measure.getActualBoundingBox-full-text.tentative</h1>
+
+<script>
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  function checkRectsMatch(rect_a, rect_b) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0);
+  }
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd '
+  ]
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      for (text of kTexts) {
+        const tm = ctx.measureText(text);
+        const rect_from_api = tm.getActualBoundingBox(0, text.length);
+        const rect_from_full_bounds = getFullTextBoundingBox(text);
+        checkRectsMatch(rect_from_api, rect_from_full_bounds)
+      }
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction ltr and no-directional-override");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  function checkRectsMatch(rect_a, rect_b) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0);
+  }
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd '
+  ]
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      for (text of kTexts) {
+        const tm = ctx.measureText(text);
+        const rect_from_api = tm.getActualBoundingBox(0, text.length);
+        const rect_from_full_bounds = getFullTextBoundingBox(text);
+        checkRectsMatch(rect_from_api, rect_from_full_bounds)
+      }
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction rtl and no-directional-override");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  function checkRectsMatch(rect_a, rect_b) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0);
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd '
+  ]
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      for (text of kTexts) {
+        text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+        const tm = ctx.measureText(text);
+        const rect_from_api = tm.getActualBoundingBox(0, text.length);
+        const rect_from_full_bounds = getFullTextBoundingBox(text);
+        checkRectsMatch(rect_from_api, rect_from_full_bounds)
+      }
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction ltr and directional-override");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  function checkRectsMatch(rect_a, rect_b) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0);
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd '
+  ]
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      for (text of kTexts) {
+        text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+        const tm = ctx.measureText(text);
+        const rect_from_api = tm.getActualBoundingBox(0, text.length);
+        const rect_from_full_bounds = getFullTextBoundingBox(text);
+        checkRectsMatch(rect_from_api, rect_from_full_bounds)
+      }
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction rtl and directional-override");
+
+</script>
+</div>
diff --git a/tests/wpt/tests/html/canvas/element/text/2d.text.measure.getActualBoundingBox.tentative.html b/tests/wpt/tests/html/canvas/element/text/2d.text.measure.getActualBoundingBox.tentative.html
new file mode 100644
index 00000000000..6f3b66a355b
--- /dev/null
+++ b/tests/wpt/tests/html/canvas/element/text/2d.text.measure.getActualBoundingBox.tentative.html
@@ -0,0 +1,502 @@
+<!DOCTYPE html>
+<!-- DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py. -->
+<title>Canvas test: 2d.text.measure.getActualBoundingBox.tentative</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/html/canvas/resources/canvas-tests.js"></script>
+<link rel="stylesheet" href="/html/canvas/resources/canvas-tests.css">
+
+<h1>2d.text.measure.getActualBoundingBox.tentative</h1>
+
+<style>
+  @font-face {
+    font-family: CanvasTest;
+    src: url("/fonts/CanvasTest.ttf");
+  }
+</style>
+<span style="font-family: CanvasTest;
+             position: absolute; visibility: hidden">A</span>
+<script>
+
+promise_test(async t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  // Returns a string a replaces the characters in text that are not in the
+  // range [start, end) with spaces.
+  function buildTestString(text, start, end) {
+    let ret = '';
+    for (let i = 0; i < text.length; ++i) {
+      if (start <= i && i < end)
+        ret += text[i];
+      else
+        ret += ' ';
+    }
+    return ret;
+  }
+
+  function checkRectsMatch(rect_a, rect_b, text, start, end) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0, `${text} :: x :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0, `${text} :: y :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0, `${text} :: width :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0, `${text} :: height :: ${start} to ${end}`);
+  }
+
+  function testForSubstring(text, start, end) {
+    const textMetrics = ctx.measureText(text);
+    const rect_from_api = textMetrics.getActualBoundingBox(start, end);
+    const rect_from_full_bounds = getFullTextBoundingBox(
+                                    buildTestString(text, start, end));
+    checkRectsMatch(rect_from_api, rect_from_full_bounds, buildTestString(text, start, end), start, end);
+  }
+
+  await document.fonts.ready;
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '0px';
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  ctx.font = '50px CanvasTest';
+  const text = 'ABCDE';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      // Full string.
+      testForSubstring(text, 0, text.length);
+      // Intermediate string.
+      testForSubstring(text, 1, text.length - 1);
+      // First character.
+      testForSubstring(text, 0, 1);
+      // Intermediate character.
+      testForSubstring(text, 2, 3);
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox(), with text align left , and 0px letter spacing.");
+
+promise_test(async t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  // Returns a string a replaces the characters in text that are not in the
+  // range [start, end) with spaces.
+  function buildTestString(text, start, end) {
+    let ret = '';
+    for (let i = 0; i < text.length; ++i) {
+      if (start <= i && i < end)
+        ret += text[i];
+      else
+        ret += ' ';
+    }
+    return ret;
+  }
+
+  function checkRectsMatch(rect_a, rect_b, text, start, end) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0, `${text} :: x :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0, `${text} :: y :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0, `${text} :: width :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0, `${text} :: height :: ${start} to ${end}`);
+  }
+
+  function testForSubstring(text, start, end) {
+    const textMetrics = ctx.measureText(text);
+    const rect_from_api = textMetrics.getActualBoundingBox(start, end);
+    const rect_from_full_bounds = getFullTextBoundingBox(
+                                    buildTestString(text, start, end));
+    checkRectsMatch(rect_from_api, rect_from_full_bounds, buildTestString(text, start, end), start, end);
+  }
+
+  await document.fonts.ready;
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '0px';
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  ctx.font = '50px CanvasTest';
+  const text = 'ABCDE';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      // Full string.
+      testForSubstring(text, 0, text.length);
+      // Intermediate string.
+      testForSubstring(text, 1, text.length - 1);
+      // First character.
+      testForSubstring(text, 0, 1);
+      // Intermediate character.
+      testForSubstring(text, 2, 3);
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox(), with text align center , and 0px letter spacing.");
+
+promise_test(async t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  // Returns a string a replaces the characters in text that are not in the
+  // range [start, end) with spaces.
+  function buildTestString(text, start, end) {
+    let ret = '';
+    for (let i = 0; i < text.length; ++i) {
+      if (start <= i && i < end)
+        ret += text[i];
+      else
+        ret += ' ';
+    }
+    return ret;
+  }
+
+  function checkRectsMatch(rect_a, rect_b, text, start, end) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0, `${text} :: x :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0, `${text} :: y :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0, `${text} :: width :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0, `${text} :: height :: ${start} to ${end}`);
+  }
+
+  function testForSubstring(text, start, end) {
+    const textMetrics = ctx.measureText(text);
+    const rect_from_api = textMetrics.getActualBoundingBox(start, end);
+    const rect_from_full_bounds = getFullTextBoundingBox(
+                                    buildTestString(text, start, end));
+    checkRectsMatch(rect_from_api, rect_from_full_bounds, buildTestString(text, start, end), start, end);
+  }
+
+  await document.fonts.ready;
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '0px';
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  ctx.font = '50px CanvasTest';
+  const text = 'ABCDE';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      // Full string.
+      testForSubstring(text, 0, text.length);
+      // Intermediate string.
+      testForSubstring(text, 1, text.length - 1);
+      // First character.
+      testForSubstring(text, 0, 1);
+      // Intermediate character.
+      testForSubstring(text, 2, 3);
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox(), with text align right , and 0px letter spacing.");
+
+promise_test(async t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  // Returns a string a replaces the characters in text that are not in the
+  // range [start, end) with spaces.
+  function buildTestString(text, start, end) {
+    let ret = '';
+    for (let i = 0; i < text.length; ++i) {
+      if (start <= i && i < end)
+        ret += text[i];
+      else
+        ret += ' ';
+    }
+    return ret;
+  }
+
+  function checkRectsMatch(rect_a, rect_b, text, start, end) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0, `${text} :: x :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0, `${text} :: y :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0, `${text} :: width :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0, `${text} :: height :: ${start} to ${end}`);
+  }
+
+  function testForSubstring(text, start, end) {
+    const textMetrics = ctx.measureText(text);
+    const rect_from_api = textMetrics.getActualBoundingBox(start, end);
+    const rect_from_full_bounds = getFullTextBoundingBox(
+                                    buildTestString(text, start, end));
+    checkRectsMatch(rect_from_api, rect_from_full_bounds, buildTestString(text, start, end), start, end);
+  }
+
+  await document.fonts.ready;
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '10px';
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  ctx.font = '50px CanvasTest';
+  const text = 'ABCDE';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      // Full string.
+      testForSubstring(text, 0, text.length);
+      // Intermediate string.
+      testForSubstring(text, 1, text.length - 1);
+      // First character.
+      testForSubstring(text, 0, 1);
+      // Intermediate character.
+      testForSubstring(text, 2, 3);
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox(), with text align left , and 10px letter spacing.");
+
+promise_test(async t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  // Returns a string a replaces the characters in text that are not in the
+  // range [start, end) with spaces.
+  function buildTestString(text, start, end) {
+    let ret = '';
+    for (let i = 0; i < text.length; ++i) {
+      if (start <= i && i < end)
+        ret += text[i];
+      else
+        ret += ' ';
+    }
+    return ret;
+  }
+
+  function checkRectsMatch(rect_a, rect_b, text, start, end) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0, `${text} :: x :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0, `${text} :: y :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0, `${text} :: width :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0, `${text} :: height :: ${start} to ${end}`);
+  }
+
+  function testForSubstring(text, start, end) {
+    const textMetrics = ctx.measureText(text);
+    const rect_from_api = textMetrics.getActualBoundingBox(start, end);
+    const rect_from_full_bounds = getFullTextBoundingBox(
+                                    buildTestString(text, start, end));
+    checkRectsMatch(rect_from_api, rect_from_full_bounds, buildTestString(text, start, end), start, end);
+  }
+
+  await document.fonts.ready;
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '10px';
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  ctx.font = '50px CanvasTest';
+  const text = 'ABCDE';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      // Full string.
+      testForSubstring(text, 0, text.length);
+      // Intermediate string.
+      testForSubstring(text, 1, text.length - 1);
+      // First character.
+      testForSubstring(text, 0, 1);
+      // Intermediate character.
+      testForSubstring(text, 2, 3);
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox(), with text align center , and 10px letter spacing.");
+
+promise_test(async t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  // Returns a string a replaces the characters in text that are not in the
+  // range [start, end) with spaces.
+  function buildTestString(text, start, end) {
+    let ret = '';
+    for (let i = 0; i < text.length; ++i) {
+      if (start <= i && i < end)
+        ret += text[i];
+      else
+        ret += ' ';
+    }
+    return ret;
+  }
+
+  function checkRectsMatch(rect_a, rect_b, text, start, end) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0, `${text} :: x :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0, `${text} :: y :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0, `${text} :: width :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0, `${text} :: height :: ${start} to ${end}`);
+  }
+
+  function testForSubstring(text, start, end) {
+    const textMetrics = ctx.measureText(text);
+    const rect_from_api = textMetrics.getActualBoundingBox(start, end);
+    const rect_from_full_bounds = getFullTextBoundingBox(
+                                    buildTestString(text, start, end));
+    checkRectsMatch(rect_from_api, rect_from_full_bounds, buildTestString(text, start, end), start, end);
+  }
+
+  await document.fonts.ready;
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '10px';
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  ctx.font = '50px CanvasTest';
+  const text = 'ABCDE';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      // Full string.
+      testForSubstring(text, 0, text.length);
+      // Intermediate string.
+      testForSubstring(text, 1, text.length - 1);
+      // First character.
+      testForSubstring(text, 0, 1);
+      // Intermediate character.
+      testForSubstring(text, 2, 3);
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox(), with text align right , and 10px letter spacing.");
+
+</script>
+</div>
diff --git a/tests/wpt/tests/html/canvas/element/text/2d.text.measure.selection-rects-baselines.tentative.html b/tests/wpt/tests/html/canvas/element/text/2d.text.measure.selection-rects-baselines.tentative.html
index 6c634b93190..4c6f8288983 100644
--- a/tests/wpt/tests/html/canvas/element/text/2d.text.measure.selection-rects-baselines.tentative.html
+++ b/tests/wpt/tests/html/canvas/element/text/2d.text.measure.selection-rects-baselines.tentative.html
@@ -33,7 +33,8 @@ _addTest(function(canvas, ctx) {
   const kTexts = [
     'UNAVAILABLE',
     '🏁🎶🏁',
-    '）（あ）（'
+    '）（あ）（',
+    '-abcd_'
   ]
 
   for (const text of kTexts) {
diff --git a/tests/wpt/tests/html/canvas/element/text/2d.text.measure.selection-rects-exceptions.tentative.html b/tests/wpt/tests/html/canvas/element/text/2d.text.measure.selection-rects-exceptions.tentative.html
index dd213d3e83b..565834280e5 100644
--- a/tests/wpt/tests/html/canvas/element/text/2d.text.measure.selection-rects-exceptions.tentative.html
+++ b/tests/wpt/tests/html/canvas/element/text/2d.text.measure.selection-rects-exceptions.tentative.html
@@ -22,7 +22,8 @@ _addTest(function(canvas, ctx) {
   const kTexts = [
     'UNAVAILABLE',
     '🏁🎶🏁',
-    '）（あ）（'
+    '）（あ）（',
+    '-abcd_'
   ]
 
   for (const text of kTexts) {
diff --git a/tests/wpt/tests/html/canvas/element/text/2d.text.measure.selection-rects.tentative.html b/tests/wpt/tests/html/canvas/element/text/2d.text.measure.selection-rects.tentative.html
index e724586f083..9de40eb61f2 100644
--- a/tests/wpt/tests/html/canvas/element/text/2d.text.measure.selection-rects.tentative.html
+++ b/tests/wpt/tests/html/canvas/element/text/2d.text.measure.selection-rects.tentative.html
@@ -5,24 +5,22 @@
 <script src="/resources/testharnessreport.js"></script>
 <script src="/html/canvas/resources/canvas-tests.js"></script>
 <link rel="stylesheet" href="/html/canvas/resources/canvas-tests.css">
-<body class="show_output">
 
 <h1>2d.text.measure.selection-rects.tentative</h1>
-<p class="desc">Check that TextMetrics::getSelectionRects() matches its DOM equivalent.</p>
 
-
-<p class="output">Actual output:</p>
-<canvas id="c" class="output" width="100" height="50"><p class="fallback">FAIL (fallback content)</p></canvas>
-
-<ul id="d"></ul>
 <script>
-var t = async_test("Check that TextMetrics::getSelectionRects() matches its DOM equivalent.");
-_addTest(function(canvas, ctx) {
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
 
   function placeAndSelectTextInDOM(text, from, to) {
     const el = document.createElement("div");
     el.innerHTML = text;
     el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'left';
+    el.style.letterSpacing = '0px';
     document.body.appendChild(el);
 
     let range = document.createRange();
@@ -30,6 +28,10 @@ _addTest(function(canvas, ctx) {
     range.setStart(el.childNodes[0], 0);
     range.setEnd(el.childNodes[0], text.length);
     const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
 
     range.setStart(el.childNodes[0], from);
     range.setEnd(el.childNodes[0], to);
@@ -42,8 +44,21 @@ _addTest(function(canvas, ctx) {
 
     document.body.removeChild(el);
 
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
     for(let i = 0 ; i < sel_rects.length ; ++i) {
-      sel_rects[i].x -= parent.x;
+      sel_rects[i].x -= parent.x + text_align_dx;
       sel_rects[i].y -= parent.y;
     }
 
@@ -62,14 +77,18 @@ _addTest(function(canvas, ctx) {
   }
 
   ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '0px';
 
   const kTexts = [
     'UNAVAILABLE',
     '🏁🎶🏁',
-    '）（あ）（'
+    '）（あ）（',
+    '-abcd_'
   ]
 
-  for (const text of kTexts) {
+  for (text of kTexts) {
     const tm = ctx.measureText(text);
     // First character.
     checkRectListsMatch(
@@ -101,7 +120,2727 @@ _addTest(function(canvas, ctx) {
       placeAndSelectTextInDOM(text, 1, 0)
     );
   }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 0px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'left';
+    el.style.letterSpacing = '0px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 0px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'center';
+    el.style.letterSpacing = '0px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 0px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'center';
+    el.style.letterSpacing = '0px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 0px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'right';
+    el.style.letterSpacing = '0px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 0px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'right';
+    el.style.letterSpacing = '0px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 0px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'left';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 10px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'left';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 10px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'center';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 10px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'center';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 10px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'right';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 10px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'right';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 10px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'left';
+    el.style.letterSpacing = '0px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 0px letter spacing, and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'left';
+    el.style.letterSpacing = '0px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 0px letter spacing, and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'center';
+    el.style.letterSpacing = '0px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 0px letter spacing, and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'center';
+    el.style.letterSpacing = '0px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 0px letter spacing, and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'right';
+    el.style.letterSpacing = '0px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 0px letter spacing, and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'right';
+    el.style.letterSpacing = '0px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 0px letter spacing, and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'left';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 10px letter spacing, and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'left';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 10px letter spacing, and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'center';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 10px letter spacing, and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'center';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 10px letter spacing, and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'right';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 10px letter spacing, and directional-override.");
+
+test(t => {
+  const canvas = document.createElement('canvas');
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'right';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 10px letter spacing, and directional-override.");
 
-});
 </script>
-
+</div>
diff --git a/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.caret-position-edge-cases.tentative.html b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.caret-position-edge-cases.tentative.html
new file mode 100644
index 00000000000..21139126fa9
--- /dev/null
+++ b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.caret-position-edge-cases.tentative.html
@@ -0,0 +1,47 @@
+<!DOCTYPE html>
+<!-- DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py. -->
+<title>OffscreenCanvas test: 2d.text.measure.caret-position-edge-cases.tentative</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/html/canvas/resources/canvas-tests.js"></script>
+
+<h1>2d.text.measure.caret-position-edge-cases.tentative</h1>
+<p class="desc">Test the edge cases for caretPositionFromPoint, where the point is at the edge of glyph and at the midpoint.</p>
+
+
+<script>
+promise_test(async t => {
+
+  var canvas = new OffscreenCanvas(100, 50);
+  var ctx = canvas.getContext('2d');
+
+  var f = new FontFace("CanvasTest", "url('/fonts/CanvasTest.ttf')");
+  f.load();
+  document.fonts.add(f);
+  await document.fonts.ready;
+  ctx.font = '50px CanvasTest';
+  ctx.direction = 'ltr';
+  ctx.align = 'left'
+  ctx.baseline = 'alphabetic'
+  tm = ctx.measureText('A');
+  const a_width = tm.width;
+  tm = ctx.measureText('B');
+  const b_width = tm.width;
+  tm = ctx.measureText('C');
+  const c_width = tm.width;
+  const epsilon = 1.0e-4;
+
+  tm = ctx.measureText('ABC');
+  _assert(tm.caretPositionFromPoint(0) == 0, "tm.caretPositionFromPoint(0) == 0");
+  _assert(tm.caretPositionFromPoint(a_width / 2) == 0, "tm.caretPositionFromPoint(a_width / 2) == 0");
+  _assert(tm.caretPositionFromPoint(a_width / 2 + 1) == 1, "tm.caretPositionFromPoint(a_width / 2 + 1) == 1");
+  _assert(tm.caretPositionFromPoint(a_width) == 1, "tm.caretPositionFromPoint(a_width) == 1");
+  _assert(tm.caretPositionFromPoint(a_width + b_width / 2) == 1, "tm.caretPositionFromPoint(a_width + b_width / 2) == 1");
+  _assert(tm.caretPositionFromPoint(a_width + b_width / 2 + 1) == 2, "tm.caretPositionFromPoint(a_width + b_width / 2 + 1) == 2");
+  _assert(tm.caretPositionFromPoint(a_width + b_width) == 2, "tm.caretPositionFromPoint(a_width + b_width) == 2");
+  _assert(tm.caretPositionFromPoint(a_width + b_width + c_width / 2) == 2, "tm.caretPositionFromPoint(a_width + b_width + c_width / 2) == 2");
+  _assert(tm.caretPositionFromPoint(a_width + b_width + c_width / 2 + 1) == 3, "tm.caretPositionFromPoint(a_width + b_width + c_width / 2 + 1) == 3");
+  _assert(tm.caretPositionFromPoint(a_width + b_width + c_width) == 3, "tm.caretPositionFromPoint(a_width + b_width + c_width) == 3");
+
+}, "Test the edge cases for caretPositionFromPoint, where the point is at the edge of glyph and at the midpoint.");
+</script>
diff --git a/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.caret-position-edge-cases.tentative.worker.js b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.caret-position-edge-cases.tentative.worker.js
new file mode 100644
index 00000000000..83539222836
--- /dev/null
+++ b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.caret-position-edge-cases.tentative.worker.js
@@ -0,0 +1,41 @@
+// DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py.
+// OffscreenCanvas test in a worker:2d.text.measure.caret-position-edge-cases.tentative
+// Description:Test the edge cases for caretPositionFromPoint, where the point is at the edge of glyph and at the midpoint.
+// Note:
+
+importScripts("/resources/testharness.js");
+importScripts("/html/canvas/resources/canvas-tests.js");
+
+promise_test(async t => {
+  var canvas = new OffscreenCanvas(100, 50);
+  var ctx = canvas.getContext('2d');
+
+  var f = new FontFace("CanvasTest", "url('/fonts/CanvasTest.ttf')");
+  f.load();
+  self.fonts.add(f);
+  await self.fonts.ready;
+  ctx.font = '50px CanvasTest';
+  ctx.direction = 'ltr';
+  ctx.align = 'left'
+  ctx.baseline = 'alphabetic'
+  tm = ctx.measureText('A');
+  const a_width = tm.width;
+  tm = ctx.measureText('B');
+  const b_width = tm.width;
+  tm = ctx.measureText('C');
+  const c_width = tm.width;
+  const epsilon = 1.0e-4;
+
+  tm = ctx.measureText('ABC');
+  _assert(tm.caretPositionFromPoint(0) == 0, "tm.caretPositionFromPoint(0) == 0");
+  _assert(tm.caretPositionFromPoint(a_width / 2) == 0, "tm.caretPositionFromPoint(a_width / 2) == 0");
+  _assert(tm.caretPositionFromPoint(a_width / 2 + 1) == 1, "tm.caretPositionFromPoint(a_width / 2 + 1) == 1");
+  _assert(tm.caretPositionFromPoint(a_width) == 1, "tm.caretPositionFromPoint(a_width) == 1");
+  _assert(tm.caretPositionFromPoint(a_width + b_width / 2) == 1, "tm.caretPositionFromPoint(a_width + b_width / 2) == 1");
+  _assert(tm.caretPositionFromPoint(a_width + b_width / 2 + 1) == 2, "tm.caretPositionFromPoint(a_width + b_width / 2 + 1) == 2");
+  _assert(tm.caretPositionFromPoint(a_width + b_width) == 2, "tm.caretPositionFromPoint(a_width + b_width) == 2");
+  _assert(tm.caretPositionFromPoint(a_width + b_width + c_width / 2) == 2, "tm.caretPositionFromPoint(a_width + b_width + c_width / 2) == 2");
+  _assert(tm.caretPositionFromPoint(a_width + b_width + c_width / 2 + 1) == 3, "tm.caretPositionFromPoint(a_width + b_width + c_width / 2 + 1) == 3");
+  _assert(tm.caretPositionFromPoint(a_width + b_width + c_width) == 3, "tm.caretPositionFromPoint(a_width + b_width + c_width) == 3");
+}, "Test the edge cases for caretPositionFromPoint, where the point is at the edge of glyph and at the midpoint.");
+done();
diff --git a/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.caret-position-edges.tentative.html b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.caret-position-edges.tentative.html
new file mode 100644
index 00000000000..29f47bf5090
--- /dev/null
+++ b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.caret-position-edges.tentative.html
@@ -0,0 +1,712 @@
+<!DOCTYPE html>
+<!-- DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py. -->
+<title>OffscreenCanvas test: 2d.text.measure.caret-position-edges.tentative</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/html/canvas/resources/canvas-tests.js"></script>
+
+<h1>2d.text.measure.caret-position-edges.tentative</h1>
+
+<script>
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('left' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('ltr' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('left' == 'start' || 'left' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('left' == 'start' || 'left' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align left.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('left' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('rtl' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('left' == 'start' || 'left' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('left' == 'start' || 'left' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align left.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('center' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('ltr' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('center' == 'start' || 'center' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('center' == 'start' || 'center' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align center.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('center' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('rtl' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('center' == 'start' || 'center' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('center' == 'start' || 'center' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align center.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('right' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('ltr' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('right' == 'start' || 'right' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('right' == 'start' || 'right' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align right.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('right' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('rtl' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('right' == 'start' || 'right' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('right' == 'start' || 'right' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align right.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('start' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('ltr' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('start' == 'start' || 'start' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('start' == 'start' || 'start' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'start';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align start.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('start' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('rtl' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('start' == 'start' || 'start' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('start' == 'start' || 'start' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'start';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align start.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('end' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('ltr' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('end' == 'start' || 'end' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('end' == 'start' || 'end' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'end';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align end.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('end' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('rtl' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('end' == 'start' || 'end' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('end' == 'start' || 'end' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'end';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align end.");
+
+</script>
diff --git a/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.caret-position-edges.tentative.worker.js b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.caret-position-edges.tentative.worker.js
new file mode 100644
index 00000000000..2cef8432d2a
--- /dev/null
+++ b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.caret-position-edges.tentative.worker.js
@@ -0,0 +1,709 @@
+// DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py.
+// OffscreenCanvas test in a worker:2d.text.measure.caret-position-edges.tentative
+// Description:
+// Note:
+
+importScripts("/resources/testharness.js");
+importScripts("/html/canvas/resources/canvas-tests.js");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('left' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('ltr' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('left' == 'start' || 'left' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('left' == 'start' || 'left' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align left.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('left' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('rtl' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('left' == 'start' || 'left' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('left' == 'start' || 'left' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align left.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('center' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('ltr' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('center' == 'start' || 'center' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('center' == 'start' || 'center' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align center.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('center' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('rtl' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('center' == 'start' || 'center' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('center' == 'start' || 'center' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align center.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('right' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('ltr' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('right' == 'start' || 'right' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('right' == 'start' || 'right' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align right.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('right' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('rtl' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('right' == 'start' || 'right' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('right' == 'start' || 'right' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align right.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('start' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('ltr' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('start' == 'start' || 'start' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('start' == 'start' || 'start' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'start';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align start.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('start' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('rtl' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('start' == 'start' || 'start' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('start' == 'start' || 'start' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'start';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align start.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('end' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('ltr' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('end' == 'start' || 'end' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('end' == 'start' || 'end' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'end';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction ltr and text align end.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function computeExpected(text, text_width, offset) {
+    expected_position = 0;
+    if ('end' == 'center' && offset == 0) {
+      return text.length / 2;
+    }
+    if ('rtl' == 'ltr') {
+      if (offset >= text_width) {
+        return text.length;
+      }
+      if (offset <= -text_width) {
+        return 0;
+      }
+      // offset must be 0.
+      if ('end' == 'start' || 'end' == 'left') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    } else {
+      if (offset >= text_width) {
+        return 0;
+      }
+      if (offset <= -text_width) {
+        return text.length;
+      }
+      // offset must be 0.
+      if ('end' == 'start' || 'end' == 'right') {
+        return 0;
+      } else {
+        return text.length;
+      }
+    }
+    return expected_position;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'end';
+  ctx.letterSpacing = '';
+
+  // The leading and trailing '-' cause the string to always follow
+  // the specified direction, even though the interior will always be ltr.
+  const text = '-0123456789-';
+
+  // Points are multiples of the string width as reported by
+  // textMetrics.width.
+  const kPoints = [
+    -2,
+    -1,
+    0,
+    1,
+    2
+  ]
+
+  const tm = ctx.measureText(text);
+  text_width = tm.width;
+  for (const multiple of kPoints) {
+    offset = multiple * text_width;
+    tm_position = tm.caretPositionFromPoint(offset);
+    expected_position = computeExpected(text, text_width, offset);
+    assert_equals(tm_position,
+                  expected_position,
+                  "for " + text + " multiple " + multiple);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() gives correct edges when the requested point is outside the range, with direction rtl and text align end.");
+
+done();
diff --git a/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.caret-position.tentative.html b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.caret-position.tentative.html
new file mode 100644
index 00000000000..53faccd652a
--- /dev/null
+++ b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.caret-position.tentative.html
@@ -0,0 +1,4072 @@
+<!DOCTYPE html>
+<!-- DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py. -->
+<title>OffscreenCanvas test: 2d.text.measure.caret-position.tentative</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/html/canvas/resources/canvas-tests.js"></script>
+
+<h1>2d.text.measure.caret-position.tentative</h1>
+
+<script>
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('left' == 'center') {
+      offset -= width / 2;
+    } else if ('left' == 'right' ||
+             ('ltr' == 'ltr' && 'left' == 'end') ||
+             ('ltr' == 'rtl' && 'left' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('left' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('left' == 'right' ||
+             ('ltr' == 'ltr' && 'left' == 'end') ||
+             ('ltr' == 'rtl' && 'left' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 0px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('left' == 'center') {
+      offset -= width / 2;
+    } else if ('left' == 'right' ||
+             ('rtl' == 'ltr' && 'left' == 'end') ||
+             ('rtl' == 'rtl' && 'left' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('left' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('left' == 'right' ||
+             ('rtl' == 'ltr' && 'left' == 'end') ||
+             ('rtl' == 'rtl' && 'left' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 0px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('center' == 'center') {
+      offset -= width / 2;
+    } else if ('center' == 'right' ||
+             ('ltr' == 'ltr' && 'center' == 'end') ||
+             ('ltr' == 'rtl' && 'center' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('center' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('center' == 'right' ||
+             ('ltr' == 'ltr' && 'center' == 'end') ||
+             ('ltr' == 'rtl' && 'center' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 0px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('center' == 'center') {
+      offset -= width / 2;
+    } else if ('center' == 'right' ||
+             ('rtl' == 'ltr' && 'center' == 'end') ||
+             ('rtl' == 'rtl' && 'center' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('center' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('center' == 'right' ||
+             ('rtl' == 'ltr' && 'center' == 'end') ||
+             ('rtl' == 'rtl' && 'center' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 0px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('right' == 'center') {
+      offset -= width / 2;
+    } else if ('right' == 'right' ||
+             ('ltr' == 'ltr' && 'right' == 'end') ||
+             ('ltr' == 'rtl' && 'right' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('right' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('right' == 'right' ||
+             ('ltr' == 'ltr' && 'right' == 'end') ||
+             ('ltr' == 'rtl' && 'right' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 0px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('right' == 'center') {
+      offset -= width / 2;
+    } else if ('right' == 'right' ||
+             ('rtl' == 'ltr' && 'right' == 'end') ||
+             ('rtl' == 'rtl' && 'right' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('right' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('right' == 'right' ||
+             ('rtl' == 'ltr' && 'right' == 'end') ||
+             ('rtl' == 'rtl' && 'right' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 0px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('start' == 'center') {
+      offset -= width / 2;
+    } else if ('start' == 'right' ||
+             ('ltr' == 'ltr' && 'start' == 'end') ||
+             ('ltr' == 'rtl' && 'start' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('start' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('start' == 'right' ||
+             ('ltr' == 'ltr' && 'start' == 'end') ||
+             ('ltr' == 'rtl' && 'start' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'start';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 0px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('start' == 'center') {
+      offset -= width / 2;
+    } else if ('start' == 'right' ||
+             ('rtl' == 'ltr' && 'start' == 'end') ||
+             ('rtl' == 'rtl' && 'start' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('start' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('start' == 'right' ||
+             ('rtl' == 'ltr' && 'start' == 'end') ||
+             ('rtl' == 'rtl' && 'start' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'start';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 0px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('end' == 'center') {
+      offset -= width / 2;
+    } else if ('end' == 'right' ||
+             ('ltr' == 'ltr' && 'end' == 'end') ||
+             ('ltr' == 'rtl' && 'end' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('end' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('end' == 'right' ||
+             ('ltr' == 'ltr' && 'end' == 'end') ||
+             ('ltr' == 'rtl' && 'end' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'end';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 0px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('end' == 'center') {
+      offset -= width / 2;
+    } else if ('end' == 'right' ||
+             ('rtl' == 'ltr' && 'end' == 'end') ||
+             ('rtl' == 'rtl' && 'end' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('end' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('end' == 'right' ||
+             ('rtl' == 'ltr' && 'end' == 'end') ||
+             ('rtl' == 'rtl' && 'end' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'end';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 0px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('left' == 'center') {
+      offset -= width / 2;
+    } else if ('left' == 'right' ||
+             ('ltr' == 'ltr' && 'left' == 'end') ||
+             ('ltr' == 'rtl' && 'left' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('left' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('left' == 'right' ||
+             ('ltr' == 'ltr' && 'left' == 'end') ||
+             ('ltr' == 'rtl' && 'left' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 10px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('left' == 'center') {
+      offset -= width / 2;
+    } else if ('left' == 'right' ||
+             ('rtl' == 'ltr' && 'left' == 'end') ||
+             ('rtl' == 'rtl' && 'left' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('left' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('left' == 'right' ||
+             ('rtl' == 'ltr' && 'left' == 'end') ||
+             ('rtl' == 'rtl' && 'left' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 10px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('center' == 'center') {
+      offset -= width / 2;
+    } else if ('center' == 'right' ||
+             ('ltr' == 'ltr' && 'center' == 'end') ||
+             ('ltr' == 'rtl' && 'center' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('center' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('center' == 'right' ||
+             ('ltr' == 'ltr' && 'center' == 'end') ||
+             ('ltr' == 'rtl' && 'center' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 10px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('center' == 'center') {
+      offset -= width / 2;
+    } else if ('center' == 'right' ||
+             ('rtl' == 'ltr' && 'center' == 'end') ||
+             ('rtl' == 'rtl' && 'center' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('center' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('center' == 'right' ||
+             ('rtl' == 'ltr' && 'center' == 'end') ||
+             ('rtl' == 'rtl' && 'center' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 10px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('right' == 'center') {
+      offset -= width / 2;
+    } else if ('right' == 'right' ||
+             ('ltr' == 'ltr' && 'right' == 'end') ||
+             ('ltr' == 'rtl' && 'right' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('right' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('right' == 'right' ||
+             ('ltr' == 'ltr' && 'right' == 'end') ||
+             ('ltr' == 'rtl' && 'right' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 10px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('right' == 'center') {
+      offset -= width / 2;
+    } else if ('right' == 'right' ||
+             ('rtl' == 'ltr' && 'right' == 'end') ||
+             ('rtl' == 'rtl' && 'right' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('right' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('right' == 'right' ||
+             ('rtl' == 'ltr' && 'right' == 'end') ||
+             ('rtl' == 'rtl' && 'right' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 10px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('start' == 'center') {
+      offset -= width / 2;
+    } else if ('start' == 'right' ||
+             ('ltr' == 'ltr' && 'start' == 'end') ||
+             ('ltr' == 'rtl' && 'start' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('start' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('start' == 'right' ||
+             ('ltr' == 'ltr' && 'start' == 'end') ||
+             ('ltr' == 'rtl' && 'start' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'start';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 10px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('start' == 'center') {
+      offset -= width / 2;
+    } else if ('start' == 'right' ||
+             ('rtl' == 'ltr' && 'start' == 'end') ||
+             ('rtl' == 'rtl' && 'start' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('start' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('start' == 'right' ||
+             ('rtl' == 'ltr' && 'start' == 'end') ||
+             ('rtl' == 'rtl' && 'start' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'start';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 10px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('end' == 'center') {
+      offset -= width / 2;
+    } else if ('end' == 'right' ||
+             ('ltr' == 'ltr' && 'end' == 'end') ||
+             ('ltr' == 'rtl' && 'end' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('end' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('end' == 'right' ||
+             ('ltr' == 'ltr' && 'end' == 'end') ||
+             ('ltr' == 'rtl' && 'end' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'end';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 10px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('end' == 'center') {
+      offset -= width / 2;
+    } else if ('end' == 'right' ||
+             ('rtl' == 'ltr' && 'end' == 'end') ||
+             ('rtl' == 'rtl' && 'end' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('end' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('end' == 'right' ||
+             ('rtl' == 'ltr' && 'end' == 'end') ||
+             ('rtl' == 'rtl' && 'end' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'end';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 10px letter spacing and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('left' == 'center') {
+      offset -= width / 2;
+    } else if ('left' == 'right' ||
+             ('ltr' == 'ltr' && 'left' == 'end') ||
+             ('ltr' == 'rtl' && 'left' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('left' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('left' == 'right' ||
+             ('ltr' == 'ltr' && 'left' == 'end') ||
+             ('ltr' == 'rtl' && 'left' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 0px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('left' == 'center') {
+      offset -= width / 2;
+    } else if ('left' == 'right' ||
+             ('rtl' == 'ltr' && 'left' == 'end') ||
+             ('rtl' == 'rtl' && 'left' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('left' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('left' == 'right' ||
+             ('rtl' == 'ltr' && 'left' == 'end') ||
+             ('rtl' == 'rtl' && 'left' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 0px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('center' == 'center') {
+      offset -= width / 2;
+    } else if ('center' == 'right' ||
+             ('ltr' == 'ltr' && 'center' == 'end') ||
+             ('ltr' == 'rtl' && 'center' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('center' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('center' == 'right' ||
+             ('ltr' == 'ltr' && 'center' == 'end') ||
+             ('ltr' == 'rtl' && 'center' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 0px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('center' == 'center') {
+      offset -= width / 2;
+    } else if ('center' == 'right' ||
+             ('rtl' == 'ltr' && 'center' == 'end') ||
+             ('rtl' == 'rtl' && 'center' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('center' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('center' == 'right' ||
+             ('rtl' == 'ltr' && 'center' == 'end') ||
+             ('rtl' == 'rtl' && 'center' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 0px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('right' == 'center') {
+      offset -= width / 2;
+    } else if ('right' == 'right' ||
+             ('ltr' == 'ltr' && 'right' == 'end') ||
+             ('ltr' == 'rtl' && 'right' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('right' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('right' == 'right' ||
+             ('ltr' == 'ltr' && 'right' == 'end') ||
+             ('ltr' == 'rtl' && 'right' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 0px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('right' == 'center') {
+      offset -= width / 2;
+    } else if ('right' == 'right' ||
+             ('rtl' == 'ltr' && 'right' == 'end') ||
+             ('rtl' == 'rtl' && 'right' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('right' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('right' == 'right' ||
+             ('rtl' == 'ltr' && 'right' == 'end') ||
+             ('rtl' == 'rtl' && 'right' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 0px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('start' == 'center') {
+      offset -= width / 2;
+    } else if ('start' == 'right' ||
+             ('ltr' == 'ltr' && 'start' == 'end') ||
+             ('ltr' == 'rtl' && 'start' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('start' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('start' == 'right' ||
+             ('ltr' == 'ltr' && 'start' == 'end') ||
+             ('ltr' == 'rtl' && 'start' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'start';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 0px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('start' == 'center') {
+      offset -= width / 2;
+    } else if ('start' == 'right' ||
+             ('rtl' == 'ltr' && 'start' == 'end') ||
+             ('rtl' == 'rtl' && 'start' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('start' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('start' == 'right' ||
+             ('rtl' == 'ltr' && 'start' == 'end') ||
+             ('rtl' == 'rtl' && 'start' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'start';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 0px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('end' == 'center') {
+      offset -= width / 2;
+    } else if ('end' == 'right' ||
+             ('ltr' == 'ltr' && 'end' == 'end') ||
+             ('ltr' == 'rtl' && 'end' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('end' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('end' == 'right' ||
+             ('ltr' == 'ltr' && 'end' == 'end') ||
+             ('ltr' == 'rtl' && 'end' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'end';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 0px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('end' == 'center') {
+      offset -= width / 2;
+    } else if ('end' == 'right' ||
+             ('rtl' == 'ltr' && 'end' == 'end') ||
+             ('rtl' == 'rtl' && 'end' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '0px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('end' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('end' == 'right' ||
+             ('rtl' == 'ltr' && 'end' == 'end') ||
+             ('rtl' == 'rtl' && 'end' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'end';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('0px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 0px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('left' == 'center') {
+      offset -= width / 2;
+    } else if ('left' == 'right' ||
+             ('ltr' == 'ltr' && 'left' == 'end') ||
+             ('ltr' == 'rtl' && 'left' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('left' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('left' == 'right' ||
+             ('ltr' == 'ltr' && 'left' == 'end') ||
+             ('ltr' == 'rtl' && 'left' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align left, 10px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('left' == 'center') {
+      offset -= width / 2;
+    } else if ('left' == 'right' ||
+             ('rtl' == 'ltr' && 'left' == 'end') ||
+             ('rtl' == 'rtl' && 'left' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('left' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('left' == 'right' ||
+             ('rtl' == 'ltr' && 'left' == 'end') ||
+             ('rtl' == 'rtl' && 'left' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align left, 10px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('center' == 'center') {
+      offset -= width / 2;
+    } else if ('center' == 'right' ||
+             ('ltr' == 'ltr' && 'center' == 'end') ||
+             ('ltr' == 'rtl' && 'center' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('center' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('center' == 'right' ||
+             ('ltr' == 'ltr' && 'center' == 'end') ||
+             ('ltr' == 'rtl' && 'center' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align center, 10px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('center' == 'center') {
+      offset -= width / 2;
+    } else if ('center' == 'right' ||
+             ('rtl' == 'ltr' && 'center' == 'end') ||
+             ('rtl' == 'rtl' && 'center' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('center' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('center' == 'right' ||
+             ('rtl' == 'ltr' && 'center' == 'end') ||
+             ('rtl' == 'rtl' && 'center' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align center, 10px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('right' == 'center') {
+      offset -= width / 2;
+    } else if ('right' == 'right' ||
+             ('ltr' == 'ltr' && 'right' == 'end') ||
+             ('ltr' == 'rtl' && 'right' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('right' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('right' == 'right' ||
+             ('ltr' == 'ltr' && 'right' == 'end') ||
+             ('ltr' == 'rtl' && 'right' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align right, 10px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('right' == 'center') {
+      offset -= width / 2;
+    } else if ('right' == 'right' ||
+             ('rtl' == 'ltr' && 'right' == 'end') ||
+             ('rtl' == 'rtl' && 'right' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('right' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('right' == 'right' ||
+             ('rtl' == 'ltr' && 'right' == 'end') ||
+             ('rtl' == 'rtl' && 'right' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align right, 10px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('start' == 'center') {
+      offset -= width / 2;
+    } else if ('start' == 'right' ||
+             ('ltr' == 'ltr' && 'start' == 'end') ||
+             ('ltr' == 'rtl' && 'start' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('start' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('start' == 'right' ||
+             ('ltr' == 'ltr' && 'start' == 'end') ||
+             ('ltr' == 'rtl' && 'start' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'start';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align start, 10px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('start' == 'center') {
+      offset -= width / 2;
+    } else if ('start' == 'right' ||
+             ('rtl' == 'ltr' && 'start' == 'end') ||
+             ('rtl' == 'rtl' && 'start' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('start' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('start' == 'right' ||
+             ('rtl' == 'ltr' && 'start' == 'end') ||
+             ('rtl' == 'rtl' && 'start' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'start';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align start, 10px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('end' == 'center') {
+      offset -= width / 2;
+    } else if ('end' == 'right' ||
+             ('ltr' == 'ltr' && 'end' == 'end') ||
+             ('ltr' == 'rtl' && 'end' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('end' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('end' == 'right' ||
+             ('ltr' == 'ltr' && 'end' == 'end') ||
+             ('ltr' == 'rtl' && 'end' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'end';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction ltr, text align end, 10px letter spacing and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function alignOffset(offset, width) {
+    if ('end' == 'center') {
+      offset -= width / 2;
+    } else if ('end' == 'right' ||
+             ('rtl' == 'ltr' && 'end' == 'end') ||
+             ('rtl' == 'rtl' && 'end' == 'start')) {
+      offset -= width;
+    }
+    return offset;
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  function placeAndMeasureTextInDOM(text, text_width, point) {
+    const el = document.createElement("p");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.letterSpacing = '10px';
+    // Put the text top left to make offsets simpler.
+    el.style.padding = '0px';
+    el.style.margin = '0px';
+    el.style.position = 'absolute';
+    el.style.x = '0px';
+    el.style.y = '0px';
+    document.body.appendChild(el);
+    text_bound = el.getBoundingClientRect();
+    text_x = text_bound.x;
+    text_y = text_bound.y + text_bound.height / 2;
+
+    // Offset to the requested point determined by textAlign and direction.
+    let text_align_dx = 0;
+    if ('end' == 'center') {
+      text_align_dx = text_width / 2;
+    } else if ('end' == 'right' ||
+             ('rtl' == 'ltr' && 'end' == 'end') ||
+             ('rtl' == 'rtl' && 'end' == 'start')) {
+      text_align_dx = text_width;
+    }
+    position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+    _assertSame(position.offsetNode.parentNode, el, "position.offsetNode.parentNode", "el");
+
+    document.body.removeChild(el);
+
+    return position.offset;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'end';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '--abcd__'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    step = 30;
+    if ('10px' == '10px') {
+      step = 40;
+    }
+
+    offset = step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width / 2;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+
+    offset = text_width - step;
+    adjusted_offset = alignOffset(offset, text_width);
+    tm_position = tm.caretPositionFromPoint(adjusted_offset);
+    doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+    assert_equals(tm_position,
+                  doc_position,
+                  "for " + text + " offset " + offset);
+  }
+}, "Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent, where possible, with direction rtl, text align end, 10px letter spacing and directional-override.");
+
+</script>
diff --git a/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.html b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.html
new file mode 100644
index 00000000000..8b41d0c830e
--- /dev/null
+++ b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.html
@@ -0,0 +1,46 @@
+<!DOCTYPE html>
+<!-- DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py. -->
+<title>OffscreenCanvas test: 2d.text.measure.getActualBoundingBox-exceptions.tentative</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/html/canvas/resources/canvas-tests.js"></script>
+
+<h1>2d.text.measure.getActualBoundingBox-exceptions.tentative</h1>
+<p class="desc">Check that TextMetrics::getActualBoundingBox() throws when using invalid indexes.</p>
+
+
+<script>
+var t = async_test("Check that TextMetrics::getActualBoundingBox() throws when using invalid indexes.");
+var t_pass = t.done.bind(t);
+var t_fail = t.step_func(function(reason) {
+    throw reason;
+});
+t.step(function() {
+
+  var canvas = new OffscreenCanvas(100, 50);
+  var ctx = canvas.getContext('2d');
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (const text of kTexts) {
+    const tm = ctx.measureText(text);
+    // Handled by the IDL binding.
+    assert_throws_js(TypeError, () => tm.getActualBoundingBox(-1, 0) );
+    assert_throws_js(TypeError, () => tm.getActualBoundingBox(0, -1) );
+    assert_throws_js(TypeError, () => tm.getActualBoundingBox(-1, -1) );
+    // Thrown in TextMetrics.
+    assert_throws_dom("IndexSizeError",
+                      () => tm.getActualBoundingBox(text.length, 0) );
+    assert_throws_dom("IndexSizeError",
+                      () => tm.getActualBoundingBox(0, text.length + 1) );
+    assert_throws_dom("IndexSizeError",
+                      () => tm.getActualBoundingBox(text.length, text.length + 1) );
+  t.done();
+
+});
+</script>
diff --git a/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.worker.js b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.worker.js
new file mode 100644
index 00000000000..84bc720399c
--- /dev/null
+++ b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-exceptions.tentative.worker.js
@@ -0,0 +1,41 @@
+// DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py.
+// OffscreenCanvas test in a worker:2d.text.measure.getActualBoundingBox-exceptions.tentative
+// Description:Check that TextMetrics::getActualBoundingBox() throws when using invalid indexes.
+// Note:
+
+importScripts("/resources/testharness.js");
+importScripts("/html/canvas/resources/canvas-tests.js");
+
+var t = async_test("Check that TextMetrics::getActualBoundingBox() throws when using invalid indexes.");
+var t_pass = t.done.bind(t);
+var t_fail = t.step_func(function(reason) {
+    throw reason;
+});
+t.step(function() {
+
+  var canvas = new OffscreenCanvas(100, 50);
+  var ctx = canvas.getContext('2d');
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (const text of kTexts) {
+    const tm = ctx.measureText(text);
+    // Handled by the IDL binding.
+    assert_throws_js(TypeError, () => tm.getActualBoundingBox(-1, 0) );
+    assert_throws_js(TypeError, () => tm.getActualBoundingBox(0, -1) );
+    assert_throws_js(TypeError, () => tm.getActualBoundingBox(-1, -1) );
+    // Thrown in TextMetrics.
+    assert_throws_dom("IndexSizeError",
+                      () => tm.getActualBoundingBox(text.length, 0) );
+    assert_throws_dom("IndexSizeError",
+                      () => tm.getActualBoundingBox(0, text.length + 1) );
+    assert_throws_dom("IndexSizeError",
+                      () => tm.getActualBoundingBox(text.length, text.length + 1) );
+  t.done();
+});
+done();
diff --git a/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-full-text.tentative.html b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-full-text.tentative.html
new file mode 100644
index 00000000000..44b107e086d
--- /dev/null
+++ b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-full-text.tentative.html
@@ -0,0 +1,276 @@
+<!DOCTYPE html>
+<!-- DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py. -->
+<title>OffscreenCanvas test: 2d.text.measure.getActualBoundingBox-full-text.tentative</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/html/canvas/resources/canvas-tests.js"></script>
+
+<h1>2d.text.measure.getActualBoundingBox-full-text.tentative</h1>
+
+<script>
+
+test(t => {
+  const canvas = new OffscreenCanvas(800, 200);
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  function checkRectsMatch(rect_a, rect_b) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0);
+  }
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd '
+  ]
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      for (text of kTexts) {
+        const tm = ctx.measureText(text);
+        const rect_from_api = tm.getActualBoundingBox(0, text.length);
+        const rect_from_full_bounds = getFullTextBoundingBox(text);
+        checkRectsMatch(rect_from_api, rect_from_full_bounds)
+      }
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction ltr and no-directional-override");
+
+test(t => {
+  const canvas = new OffscreenCanvas(800, 200);
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  function checkRectsMatch(rect_a, rect_b) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0);
+  }
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd '
+  ]
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      for (text of kTexts) {
+        const tm = ctx.measureText(text);
+        const rect_from_api = tm.getActualBoundingBox(0, text.length);
+        const rect_from_full_bounds = getFullTextBoundingBox(text);
+        checkRectsMatch(rect_from_api, rect_from_full_bounds)
+      }
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction rtl and no-directional-override");
+
+test(t => {
+  const canvas = new OffscreenCanvas(800, 200);
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  function checkRectsMatch(rect_a, rect_b) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0);
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd '
+  ]
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      for (text of kTexts) {
+        text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+        const tm = ctx.measureText(text);
+        const rect_from_api = tm.getActualBoundingBox(0, text.length);
+        const rect_from_full_bounds = getFullTextBoundingBox(text);
+        checkRectsMatch(rect_from_api, rect_from_full_bounds)
+      }
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction ltr and directional-override");
+
+test(t => {
+  const canvas = new OffscreenCanvas(800, 200);
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  function checkRectsMatch(rect_a, rect_b) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0);
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd '
+  ]
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      for (text of kTexts) {
+        text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+        const tm = ctx.measureText(text);
+        const rect_from_api = tm.getActualBoundingBox(0, text.length);
+        const rect_from_full_bounds = getFullTextBoundingBox(text);
+        checkRectsMatch(rect_from_api, rect_from_full_bounds)
+      }
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction rtl and directional-override");
+
+</script>
diff --git a/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-full-text.tentative.worker.js b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-full-text.tentative.worker.js
new file mode 100644
index 00000000000..54a4cb41154
--- /dev/null
+++ b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox-full-text.tentative.worker.js
@@ -0,0 +1,273 @@
+// DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py.
+// OffscreenCanvas test in a worker:2d.text.measure.getActualBoundingBox-full-text.tentative
+// Description:
+// Note:
+
+importScripts("/resources/testharness.js");
+importScripts("/html/canvas/resources/canvas-tests.js");
+
+test(t => {
+  const canvas = new OffscreenCanvas(800, 200);
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  function checkRectsMatch(rect_a, rect_b) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0);
+  }
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd '
+  ]
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      for (text of kTexts) {
+        const tm = ctx.measureText(text);
+        const rect_from_api = tm.getActualBoundingBox(0, text.length);
+        const rect_from_full_bounds = getFullTextBoundingBox(text);
+        checkRectsMatch(rect_from_api, rect_from_full_bounds)
+      }
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction ltr and no-directional-override");
+
+test(t => {
+  const canvas = new OffscreenCanvas(800, 200);
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  function checkRectsMatch(rect_a, rect_b) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0);
+  }
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd '
+  ]
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      for (text of kTexts) {
+        const tm = ctx.measureText(text);
+        const rect_from_api = tm.getActualBoundingBox(0, text.length);
+        const rect_from_full_bounds = getFullTextBoundingBox(text);
+        checkRectsMatch(rect_from_api, rect_from_full_bounds)
+      }
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction rtl and no-directional-override");
+
+test(t => {
+  const canvas = new OffscreenCanvas(800, 200);
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  function checkRectsMatch(rect_a, rect_b) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0);
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd '
+  ]
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      for (text of kTexts) {
+        text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+        const tm = ctx.measureText(text);
+        const rect_from_api = tm.getActualBoundingBox(0, text.length);
+        const rect_from_full_bounds = getFullTextBoundingBox(text);
+        checkRectsMatch(rect_from_api, rect_from_full_bounds)
+      }
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction ltr and directional-override");
+
+test(t => {
+  const canvas = new OffscreenCanvas(800, 200);
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  function checkRectsMatch(rect_a, rect_b) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0);
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd '
+  ]
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      for (text of kTexts) {
+        text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+        const tm = ctx.measureText(text);
+        const rect_from_api = tm.getActualBoundingBox(0, text.length);
+        const rect_from_full_bounds = getFullTextBoundingBox(text);
+        checkRectsMatch(rect_from_api, rect_from_full_bounds)
+      }
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox() for the full length of the string for some edge cases, with direction rtl and directional-override");
+
+done();
diff --git a/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox.tentative.html b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox.tentative.html
new file mode 100644
index 00000000000..e6a2b070205
--- /dev/null
+++ b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox.tentative.html
@@ -0,0 +1,510 @@
+<!DOCTYPE html>
+<!-- DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py. -->
+<title>OffscreenCanvas test: 2d.text.measure.getActualBoundingBox.tentative</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/html/canvas/resources/canvas-tests.js"></script>
+
+<h1>2d.text.measure.getActualBoundingBox.tentative</h1>
+
+<script>
+
+promise_test(async t => {
+  const canvas = new OffscreenCanvas(800, 200);
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  // Returns a string a replaces the characters in text that are not in the
+  // range [start, end) with spaces.
+  function buildTestString(text, start, end) {
+    let ret = '';
+    for (let i = 0; i < text.length; ++i) {
+      if (start <= i && i < end)
+        ret += text[i];
+      else
+        ret += ' ';
+    }
+    return ret;
+  }
+
+  function checkRectsMatch(rect_a, rect_b, text, start, end) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0, `${text} :: x :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0, `${text} :: y :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0, `${text} :: width :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0, `${text} :: height :: ${start} to ${end}`);
+  }
+
+  function testForSubstring(text, start, end) {
+    const textMetrics = ctx.measureText(text);
+    const rect_from_api = textMetrics.getActualBoundingBox(start, end);
+    const rect_from_full_bounds = getFullTextBoundingBox(
+                                    buildTestString(text, start, end));
+    checkRectsMatch(rect_from_api, rect_from_full_bounds, buildTestString(text, start, end), start, end);
+  }
+
+  var f = new FontFace("CanvasTest", "url('/fonts/CanvasTest.ttf')");
+  f.load();
+  document.fonts.add(f);
+  await document.fonts.ready;
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '0px';
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  ctx.font = '50px CanvasTest';
+  const text = 'ABCDE';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      // Full string.
+      testForSubstring(text, 0, text.length);
+      // Intermediate string.
+      testForSubstring(text, 1, text.length - 1);
+      // First character.
+      testForSubstring(text, 0, 1);
+      // Intermediate character.
+      testForSubstring(text, 2, 3);
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox(), with text align left , and 0px letter spacing.");
+
+promise_test(async t => {
+  const canvas = new OffscreenCanvas(800, 200);
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  // Returns a string a replaces the characters in text that are not in the
+  // range [start, end) with spaces.
+  function buildTestString(text, start, end) {
+    let ret = '';
+    for (let i = 0; i < text.length; ++i) {
+      if (start <= i && i < end)
+        ret += text[i];
+      else
+        ret += ' ';
+    }
+    return ret;
+  }
+
+  function checkRectsMatch(rect_a, rect_b, text, start, end) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0, `${text} :: x :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0, `${text} :: y :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0, `${text} :: width :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0, `${text} :: height :: ${start} to ${end}`);
+  }
+
+  function testForSubstring(text, start, end) {
+    const textMetrics = ctx.measureText(text);
+    const rect_from_api = textMetrics.getActualBoundingBox(start, end);
+    const rect_from_full_bounds = getFullTextBoundingBox(
+                                    buildTestString(text, start, end));
+    checkRectsMatch(rect_from_api, rect_from_full_bounds, buildTestString(text, start, end), start, end);
+  }
+
+  var f = new FontFace("CanvasTest", "url('/fonts/CanvasTest.ttf')");
+  f.load();
+  document.fonts.add(f);
+  await document.fonts.ready;
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '0px';
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  ctx.font = '50px CanvasTest';
+  const text = 'ABCDE';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      // Full string.
+      testForSubstring(text, 0, text.length);
+      // Intermediate string.
+      testForSubstring(text, 1, text.length - 1);
+      // First character.
+      testForSubstring(text, 0, 1);
+      // Intermediate character.
+      testForSubstring(text, 2, 3);
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox(), with text align center , and 0px letter spacing.");
+
+promise_test(async t => {
+  const canvas = new OffscreenCanvas(800, 200);
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  // Returns a string a replaces the characters in text that are not in the
+  // range [start, end) with spaces.
+  function buildTestString(text, start, end) {
+    let ret = '';
+    for (let i = 0; i < text.length; ++i) {
+      if (start <= i && i < end)
+        ret += text[i];
+      else
+        ret += ' ';
+    }
+    return ret;
+  }
+
+  function checkRectsMatch(rect_a, rect_b, text, start, end) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0, `${text} :: x :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0, `${text} :: y :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0, `${text} :: width :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0, `${text} :: height :: ${start} to ${end}`);
+  }
+
+  function testForSubstring(text, start, end) {
+    const textMetrics = ctx.measureText(text);
+    const rect_from_api = textMetrics.getActualBoundingBox(start, end);
+    const rect_from_full_bounds = getFullTextBoundingBox(
+                                    buildTestString(text, start, end));
+    checkRectsMatch(rect_from_api, rect_from_full_bounds, buildTestString(text, start, end), start, end);
+  }
+
+  var f = new FontFace("CanvasTest", "url('/fonts/CanvasTest.ttf')");
+  f.load();
+  document.fonts.add(f);
+  await document.fonts.ready;
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '0px';
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  ctx.font = '50px CanvasTest';
+  const text = 'ABCDE';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      // Full string.
+      testForSubstring(text, 0, text.length);
+      // Intermediate string.
+      testForSubstring(text, 1, text.length - 1);
+      // First character.
+      testForSubstring(text, 0, 1);
+      // Intermediate character.
+      testForSubstring(text, 2, 3);
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox(), with text align right , and 0px letter spacing.");
+
+promise_test(async t => {
+  const canvas = new OffscreenCanvas(800, 200);
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  // Returns a string a replaces the characters in text that are not in the
+  // range [start, end) with spaces.
+  function buildTestString(text, start, end) {
+    let ret = '';
+    for (let i = 0; i < text.length; ++i) {
+      if (start <= i && i < end)
+        ret += text[i];
+      else
+        ret += ' ';
+    }
+    return ret;
+  }
+
+  function checkRectsMatch(rect_a, rect_b, text, start, end) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0, `${text} :: x :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0, `${text} :: y :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0, `${text} :: width :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0, `${text} :: height :: ${start} to ${end}`);
+  }
+
+  function testForSubstring(text, start, end) {
+    const textMetrics = ctx.measureText(text);
+    const rect_from_api = textMetrics.getActualBoundingBox(start, end);
+    const rect_from_full_bounds = getFullTextBoundingBox(
+                                    buildTestString(text, start, end));
+    checkRectsMatch(rect_from_api, rect_from_full_bounds, buildTestString(text, start, end), start, end);
+  }
+
+  var f = new FontFace("CanvasTest", "url('/fonts/CanvasTest.ttf')");
+  f.load();
+  document.fonts.add(f);
+  await document.fonts.ready;
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '10px';
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  ctx.font = '50px CanvasTest';
+  const text = 'ABCDE';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      // Full string.
+      testForSubstring(text, 0, text.length);
+      // Intermediate string.
+      testForSubstring(text, 1, text.length - 1);
+      // First character.
+      testForSubstring(text, 0, 1);
+      // Intermediate character.
+      testForSubstring(text, 2, 3);
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox(), with text align left , and 10px letter spacing.");
+
+promise_test(async t => {
+  const canvas = new OffscreenCanvas(800, 200);
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  // Returns a string a replaces the characters in text that are not in the
+  // range [start, end) with spaces.
+  function buildTestString(text, start, end) {
+    let ret = '';
+    for (let i = 0; i < text.length; ++i) {
+      if (start <= i && i < end)
+        ret += text[i];
+      else
+        ret += ' ';
+    }
+    return ret;
+  }
+
+  function checkRectsMatch(rect_a, rect_b, text, start, end) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0, `${text} :: x :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0, `${text} :: y :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0, `${text} :: width :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0, `${text} :: height :: ${start} to ${end}`);
+  }
+
+  function testForSubstring(text, start, end) {
+    const textMetrics = ctx.measureText(text);
+    const rect_from_api = textMetrics.getActualBoundingBox(start, end);
+    const rect_from_full_bounds = getFullTextBoundingBox(
+                                    buildTestString(text, start, end));
+    checkRectsMatch(rect_from_api, rect_from_full_bounds, buildTestString(text, start, end), start, end);
+  }
+
+  var f = new FontFace("CanvasTest", "url('/fonts/CanvasTest.ttf')");
+  f.load();
+  document.fonts.add(f);
+  await document.fonts.ready;
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '10px';
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  ctx.font = '50px CanvasTest';
+  const text = 'ABCDE';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      // Full string.
+      testForSubstring(text, 0, text.length);
+      // Intermediate string.
+      testForSubstring(text, 1, text.length - 1);
+      // First character.
+      testForSubstring(text, 0, 1);
+      // Intermediate character.
+      testForSubstring(text, 2, 3);
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox(), with text align center , and 10px letter spacing.");
+
+promise_test(async t => {
+  const canvas = new OffscreenCanvas(800, 200);
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  // Returns a string a replaces the characters in text that are not in the
+  // range [start, end) with spaces.
+  function buildTestString(text, start, end) {
+    let ret = '';
+    for (let i = 0; i < text.length; ++i) {
+      if (start <= i && i < end)
+        ret += text[i];
+      else
+        ret += ' ';
+    }
+    return ret;
+  }
+
+  function checkRectsMatch(rect_a, rect_b, text, start, end) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0, `${text} :: x :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0, `${text} :: y :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0, `${text} :: width :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0, `${text} :: height :: ${start} to ${end}`);
+  }
+
+  function testForSubstring(text, start, end) {
+    const textMetrics = ctx.measureText(text);
+    const rect_from_api = textMetrics.getActualBoundingBox(start, end);
+    const rect_from_full_bounds = getFullTextBoundingBox(
+                                    buildTestString(text, start, end));
+    checkRectsMatch(rect_from_api, rect_from_full_bounds, buildTestString(text, start, end), start, end);
+  }
+
+  var f = new FontFace("CanvasTest", "url('/fonts/CanvasTest.ttf')");
+  f.load();
+  document.fonts.add(f);
+  await document.fonts.ready;
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '10px';
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  ctx.font = '50px CanvasTest';
+  const text = 'ABCDE';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      // Full string.
+      testForSubstring(text, 0, text.length);
+      // Intermediate string.
+      testForSubstring(text, 1, text.length - 1);
+      // First character.
+      testForSubstring(text, 0, 1);
+      // Intermediate character.
+      testForSubstring(text, 2, 3);
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox(), with text align right , and 10px letter spacing.");
+
+</script>
diff --git a/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox.tentative.worker.js b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox.tentative.worker.js
new file mode 100644
index 00000000000..9530d177658
--- /dev/null
+++ b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.getActualBoundingBox.tentative.worker.js
@@ -0,0 +1,507 @@
+// DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py.
+// OffscreenCanvas test in a worker:2d.text.measure.getActualBoundingBox.tentative
+// Description:
+// Note:
+
+importScripts("/resources/testharness.js");
+importScripts("/html/canvas/resources/canvas-tests.js");
+
+promise_test(async t => {
+  const canvas = new OffscreenCanvas(800, 200);
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  // Returns a string a replaces the characters in text that are not in the
+  // range [start, end) with spaces.
+  function buildTestString(text, start, end) {
+    let ret = '';
+    for (let i = 0; i < text.length; ++i) {
+      if (start <= i && i < end)
+        ret += text[i];
+      else
+        ret += ' ';
+    }
+    return ret;
+  }
+
+  function checkRectsMatch(rect_a, rect_b, text, start, end) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0, `${text} :: x :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0, `${text} :: y :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0, `${text} :: width :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0, `${text} :: height :: ${start} to ${end}`);
+  }
+
+  function testForSubstring(text, start, end) {
+    const textMetrics = ctx.measureText(text);
+    const rect_from_api = textMetrics.getActualBoundingBox(start, end);
+    const rect_from_full_bounds = getFullTextBoundingBox(
+                                    buildTestString(text, start, end));
+    checkRectsMatch(rect_from_api, rect_from_full_bounds, buildTestString(text, start, end), start, end);
+  }
+
+  var f = new FontFace("CanvasTest", "url('/fonts/CanvasTest.ttf')");
+  f.load();
+  self.fonts.add(f);
+  await self.fonts.ready;
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '0px';
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  ctx.font = '50px CanvasTest';
+  const text = 'ABCDE';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      // Full string.
+      testForSubstring(text, 0, text.length);
+      // Intermediate string.
+      testForSubstring(text, 1, text.length - 1);
+      // First character.
+      testForSubstring(text, 0, 1);
+      // Intermediate character.
+      testForSubstring(text, 2, 3);
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox(), with text align left , and 0px letter spacing.");
+
+promise_test(async t => {
+  const canvas = new OffscreenCanvas(800, 200);
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  // Returns a string a replaces the characters in text that are not in the
+  // range [start, end) with spaces.
+  function buildTestString(text, start, end) {
+    let ret = '';
+    for (let i = 0; i < text.length; ++i) {
+      if (start <= i && i < end)
+        ret += text[i];
+      else
+        ret += ' ';
+    }
+    return ret;
+  }
+
+  function checkRectsMatch(rect_a, rect_b, text, start, end) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0, `${text} :: x :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0, `${text} :: y :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0, `${text} :: width :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0, `${text} :: height :: ${start} to ${end}`);
+  }
+
+  function testForSubstring(text, start, end) {
+    const textMetrics = ctx.measureText(text);
+    const rect_from_api = textMetrics.getActualBoundingBox(start, end);
+    const rect_from_full_bounds = getFullTextBoundingBox(
+                                    buildTestString(text, start, end));
+    checkRectsMatch(rect_from_api, rect_from_full_bounds, buildTestString(text, start, end), start, end);
+  }
+
+  var f = new FontFace("CanvasTest", "url('/fonts/CanvasTest.ttf')");
+  f.load();
+  self.fonts.add(f);
+  await self.fonts.ready;
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '0px';
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  ctx.font = '50px CanvasTest';
+  const text = 'ABCDE';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      // Full string.
+      testForSubstring(text, 0, text.length);
+      // Intermediate string.
+      testForSubstring(text, 1, text.length - 1);
+      // First character.
+      testForSubstring(text, 0, 1);
+      // Intermediate character.
+      testForSubstring(text, 2, 3);
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox(), with text align center , and 0px letter spacing.");
+
+promise_test(async t => {
+  const canvas = new OffscreenCanvas(800, 200);
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  // Returns a string a replaces the characters in text that are not in the
+  // range [start, end) with spaces.
+  function buildTestString(text, start, end) {
+    let ret = '';
+    for (let i = 0; i < text.length; ++i) {
+      if (start <= i && i < end)
+        ret += text[i];
+      else
+        ret += ' ';
+    }
+    return ret;
+  }
+
+  function checkRectsMatch(rect_a, rect_b, text, start, end) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0, `${text} :: x :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0, `${text} :: y :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0, `${text} :: width :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0, `${text} :: height :: ${start} to ${end}`);
+  }
+
+  function testForSubstring(text, start, end) {
+    const textMetrics = ctx.measureText(text);
+    const rect_from_api = textMetrics.getActualBoundingBox(start, end);
+    const rect_from_full_bounds = getFullTextBoundingBox(
+                                    buildTestString(text, start, end));
+    checkRectsMatch(rect_from_api, rect_from_full_bounds, buildTestString(text, start, end), start, end);
+  }
+
+  var f = new FontFace("CanvasTest", "url('/fonts/CanvasTest.ttf')");
+  f.load();
+  self.fonts.add(f);
+  await self.fonts.ready;
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '0px';
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  ctx.font = '50px CanvasTest';
+  const text = 'ABCDE';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      // Full string.
+      testForSubstring(text, 0, text.length);
+      // Intermediate string.
+      testForSubstring(text, 1, text.length - 1);
+      // First character.
+      testForSubstring(text, 0, 1);
+      // Intermediate character.
+      testForSubstring(text, 2, 3);
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox(), with text align right , and 0px letter spacing.");
+
+promise_test(async t => {
+  const canvas = new OffscreenCanvas(800, 200);
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  // Returns a string a replaces the characters in text that are not in the
+  // range [start, end) with spaces.
+  function buildTestString(text, start, end) {
+    let ret = '';
+    for (let i = 0; i < text.length; ++i) {
+      if (start <= i && i < end)
+        ret += text[i];
+      else
+        ret += ' ';
+    }
+    return ret;
+  }
+
+  function checkRectsMatch(rect_a, rect_b, text, start, end) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0, `${text} :: x :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0, `${text} :: y :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0, `${text} :: width :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0, `${text} :: height :: ${start} to ${end}`);
+  }
+
+  function testForSubstring(text, start, end) {
+    const textMetrics = ctx.measureText(text);
+    const rect_from_api = textMetrics.getActualBoundingBox(start, end);
+    const rect_from_full_bounds = getFullTextBoundingBox(
+                                    buildTestString(text, start, end));
+    checkRectsMatch(rect_from_api, rect_from_full_bounds, buildTestString(text, start, end), start, end);
+  }
+
+  var f = new FontFace("CanvasTest", "url('/fonts/CanvasTest.ttf')");
+  f.load();
+  self.fonts.add(f);
+  await self.fonts.ready;
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '10px';
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  ctx.font = '50px CanvasTest';
+  const text = 'ABCDE';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      // Full string.
+      testForSubstring(text, 0, text.length);
+      // Intermediate string.
+      testForSubstring(text, 1, text.length - 1);
+      // First character.
+      testForSubstring(text, 0, 1);
+      // Intermediate character.
+      testForSubstring(text, 2, 3);
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox(), with text align left , and 10px letter spacing.");
+
+promise_test(async t => {
+  const canvas = new OffscreenCanvas(800, 200);
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  // Returns a string a replaces the characters in text that are not in the
+  // range [start, end) with spaces.
+  function buildTestString(text, start, end) {
+    let ret = '';
+    for (let i = 0; i < text.length; ++i) {
+      if (start <= i && i < end)
+        ret += text[i];
+      else
+        ret += ' ';
+    }
+    return ret;
+  }
+
+  function checkRectsMatch(rect_a, rect_b, text, start, end) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0, `${text} :: x :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0, `${text} :: y :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0, `${text} :: width :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0, `${text} :: height :: ${start} to ${end}`);
+  }
+
+  function testForSubstring(text, start, end) {
+    const textMetrics = ctx.measureText(text);
+    const rect_from_api = textMetrics.getActualBoundingBox(start, end);
+    const rect_from_full_bounds = getFullTextBoundingBox(
+                                    buildTestString(text, start, end));
+    checkRectsMatch(rect_from_api, rect_from_full_bounds, buildTestString(text, start, end), start, end);
+  }
+
+  var f = new FontFace("CanvasTest", "url('/fonts/CanvasTest.ttf')");
+  f.load();
+  self.fonts.add(f);
+  await self.fonts.ready;
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '10px';
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  ctx.font = '50px CanvasTest';
+  const text = 'ABCDE';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      // Full string.
+      testForSubstring(text, 0, text.length);
+      // Intermediate string.
+      testForSubstring(text, 1, text.length - 1);
+      // First character.
+      testForSubstring(text, 0, 1);
+      // Intermediate character.
+      testForSubstring(text, 2, 3);
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox(), with text align center , and 10px letter spacing.");
+
+promise_test(async t => {
+  const canvas = new OffscreenCanvas(800, 200);
+  const ctx = canvas.getContext('2d');
+
+  // Use measureText to create a rect for the whole text
+  function getFullTextBoundingBox(text) {
+    const tm = ctx.measureText(text);
+    return {
+      x: -tm.actualBoundingBoxLeft,
+      y: -tm.actualBoundingBoxAscent,
+      width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+      height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+    };
+  }
+
+  // Returns a string a replaces the characters in text that are not in the
+  // range [start, end) with spaces.
+  function buildTestString(text, start, end) {
+    let ret = '';
+    for (let i = 0; i < text.length; ++i) {
+      if (start <= i && i < end)
+        ret += text[i];
+      else
+        ret += ' ';
+    }
+    return ret;
+  }
+
+  function checkRectsMatch(rect_a, rect_b, text, start, end) {
+    assert_approx_equals(rect_a.x, rect_b.x, 1.0, `${text} :: x :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.y, rect_b.y, 1.0, `${text} :: y :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.width, rect_b.width, 1.0, `${text} :: width :: ${start} to ${end}`);
+    assert_approx_equals(rect_a.height, rect_b.height, 1.0, `${text} :: height :: ${start} to ${end}`);
+  }
+
+  function testForSubstring(text, start, end) {
+    const textMetrics = ctx.measureText(text);
+    const rect_from_api = textMetrics.getActualBoundingBox(start, end);
+    const rect_from_full_bounds = getFullTextBoundingBox(
+                                    buildTestString(text, start, end));
+    checkRectsMatch(rect_from_api, rect_from_full_bounds, buildTestString(text, start, end), start, end);
+  }
+
+  var f = new FontFace("CanvasTest", "url('/fonts/CanvasTest.ttf')");
+  f.load();
+  self.fonts.add(f);
+  await self.fonts.ready;
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '10px';
+
+  const kAligns = [
+    'left',
+    'center',
+    'right',
+  ];
+
+  const kBaselines = [
+    'top',
+    'hanging',
+    'middle',
+    'alphabetic',
+    'ideographic',
+    'bottom',
+  ];
+
+  ctx.font = '50px CanvasTest';
+  const text = 'ABCDE';
+  for (const align of kAligns) {
+    for (const baseline of kBaselines) {
+      ctx.textAlign = align;
+      ctx.textBaseline = baseline;
+      // Full string.
+      testForSubstring(text, 0, text.length);
+      // Intermediate string.
+      testForSubstring(text, 1, text.length - 1);
+      // First character.
+      testForSubstring(text, 0, 1);
+      // Intermediate character.
+      testForSubstring(text, 2, 3);
+    }
+  }
+}, "Test TextMetrics::getActualBoundingBox(), with text align right , and 10px letter spacing.");
+
+done();
diff --git a/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.selection-rects-baselines.tentative.html b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.selection-rects-baselines.tentative.html
index 818a63ef65f..23220d4a446 100644
--- a/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.selection-rects-baselines.tentative.html
+++ b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.selection-rects-baselines.tentative.html
@@ -34,7 +34,8 @@ t.step(function() {
   const kTexts = [
     'UNAVAILABLE',
     '🏁🎶🏁',
-    '）（あ）（'
+    '）（あ）（',
+    '-abcd_'
   ]
 
   for (const text of kTexts) {
diff --git a/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.selection-rects-baselines.tentative.worker.js b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.selection-rects-baselines.tentative.worker.js
index 56a8d2799a0..6d275c042eb 100644
--- a/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.selection-rects-baselines.tentative.worker.js
+++ b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.selection-rects-baselines.tentative.worker.js
@@ -30,7 +30,8 @@ t.step(function() {
   const kTexts = [
     'UNAVAILABLE',
     '🏁🎶🏁',
-    '）（あ）（'
+    '）（あ）（',
+    '-abcd_'
   ]
 
   for (const text of kTexts) {
diff --git a/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.selection-rects-exceptions.tentative.html b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.selection-rects-exceptions.tentative.html
index 06ffeacd037..518fbc654aa 100644
--- a/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.selection-rects-exceptions.tentative.html
+++ b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.selection-rects-exceptions.tentative.html
@@ -23,7 +23,8 @@ t.step(function() {
   const kTexts = [
     'UNAVAILABLE',
     '🏁🎶🏁',
-    '）（あ）（'
+    '）（あ）（',
+    '-abcd_'
   ]
 
   for (const text of kTexts) {
diff --git a/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.selection-rects-exceptions.tentative.worker.js b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.selection-rects-exceptions.tentative.worker.js
index 1ec8bc49731..a3fefb3b253 100644
--- a/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.selection-rects-exceptions.tentative.worker.js
+++ b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.selection-rects-exceptions.tentative.worker.js
@@ -19,7 +19,8 @@ t.step(function() {
   const kTexts = [
     'UNAVAILABLE',
     '🏁🎶🏁',
-    '）（あ）（'
+    '）（あ）（',
+    '-abcd_'
   ]
 
   for (const text of kTexts) {
diff --git a/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.selection-rects.tentative.html b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.selection-rects.tentative.html
index e8574850fac..6c0261e1534 100644
--- a/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.selection-rects.tentative.html
+++ b/tests/wpt/tests/html/canvas/offscreen/text/2d.text.measure.selection-rects.tentative.html
@@ -6,24 +6,20 @@
 <script src="/html/canvas/resources/canvas-tests.js"></script>
 
 <h1>2d.text.measure.selection-rects.tentative</h1>
-<p class="desc">Check that TextMetrics::getSelectionRects() matches its DOM equivalent.</p>
-
 
 <script>
-var t = async_test("Check that TextMetrics::getSelectionRects() matches its DOM equivalent.");
-var t_pass = t.done.bind(t);
-var t_fail = t.step_func(function(reason) {
-    throw reason;
-});
-t.step(function() {
 
-  var canvas = new OffscreenCanvas(100, 50);
-  var ctx = canvas.getContext('2d');
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
 
   function placeAndSelectTextInDOM(text, from, to) {
     const el = document.createElement("div");
     el.innerHTML = text;
     el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'left';
+    el.style.letterSpacing = '0px';
     document.body.appendChild(el);
 
     let range = document.createRange();
@@ -31,6 +27,10 @@ t.step(function() {
     range.setStart(el.childNodes[0], 0);
     range.setEnd(el.childNodes[0], text.length);
     const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
 
     range.setStart(el.childNodes[0], from);
     range.setEnd(el.childNodes[0], to);
@@ -43,8 +43,21 @@ t.step(function() {
 
     document.body.removeChild(el);
 
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
     for(let i = 0 ; i < sel_rects.length ; ++i) {
-      sel_rects[i].x -= parent.x;
+      sel_rects[i].x -= parent.x + text_align_dx;
       sel_rects[i].y -= parent.y;
     }
 
@@ -63,14 +76,18 @@ t.step(function() {
   }
 
   ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '0px';
 
   const kTexts = [
     'UNAVAILABLE',
     '🏁🎶🏁',
-    '）（あ）（'
+    '）（あ）（',
+    '-abcd_'
   ]
 
-  for (const text of kTexts) {
+  for (text of kTexts) {
     const tm = ctx.measureText(text);
     // First character.
     checkRectListsMatch(
@@ -102,7 +119,2726 @@ t.step(function() {
       placeAndSelectTextInDOM(text, 1, 0)
     );
   }
-  t.done();
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 0px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'left';
+    el.style.letterSpacing = '0px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 0px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'center';
+    el.style.letterSpacing = '0px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 0px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'center';
+    el.style.letterSpacing = '0px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 0px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'right';
+    el.style.letterSpacing = '0px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 0px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'right';
+    el.style.letterSpacing = '0px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 0px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'left';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 10px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'left';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 10px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'center';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 10px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'center';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 10px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'right';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 10px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'right';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 10px letter spacing, and no-directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'left';
+    el.style.letterSpacing = '0px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 0px letter spacing, and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'left';
+    el.style.letterSpacing = '0px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 0px letter spacing, and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'center';
+    el.style.letterSpacing = '0px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 0px letter spacing, and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'center';
+    el.style.letterSpacing = '0px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 0px letter spacing, and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'right';
+    el.style.letterSpacing = '0px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 0px letter spacing, and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'right';
+    el.style.letterSpacing = '0px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '0px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 0px letter spacing, and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'left';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align left, 10px letter spacing, and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'left';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'left';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align left, 10px letter spacing, and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'center';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align center, 10px letter spacing, and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'center';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'center';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align center, 10px letter spacing, and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'ltr';
+    el.style.textAlign = 'right';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'ltr';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction ltr, text align right, 10px letter spacing, and directional-override.");
+
+test(t => {
+  const canvas = new OffscreenCanvas(100, 50);
+  const ctx = canvas.getContext('2d');
+
+  function placeAndSelectTextInDOM(text, from, to) {
+    const el = document.createElement("div");
+    el.innerHTML = text;
+    el.style.font = '50px sans-serif';
+    el.style.direction = 'rtl';
+    el.style.textAlign = 'right';
+    el.style.letterSpacing = '10px';
+    document.body.appendChild(el);
+
+    let range = document.createRange();
+
+    range.setStart(el.childNodes[0], 0);
+    range.setEnd(el.childNodes[0], text.length);
+    const parent = range.getClientRects()[0];
+    let width = 0;
+    for (const rect of range.getClientRects()) {
+      width += rect.width;
+    }
+
+    range.setStart(el.childNodes[0], from);
+    range.setEnd(el.childNodes[0], to);
+
+    let sel = window.getSelection();
+    sel.removeAllRanges();
+    sel.addRange(range);
+
+    let sel_rects = sel.getRangeAt(0).getClientRects();
+
+    document.body.removeChild(el);
+
+    // Offset to the alignment point determined by textAlign.
+    let text_align_dx;
+    switch (el.style.textAlign) {
+      case 'right':
+        text_align_dx = width;
+        break;
+      case 'center':
+        text_align_dx = width / 2;
+        break;
+      default:
+        text_align_dx = 0;
+    }
+
+    for(let i = 0 ; i < sel_rects.length ; ++i) {
+      sel_rects[i].x -= parent.x + text_align_dx;
+      sel_rects[i].y -= parent.y;
+    }
+
+    return sel_rects;
+  }
+
+  function checkRectListsMatch(list_a, list_b) {
+    _assertSame(list_a.length, list_b.length, "list_a.length", "list_b.length");
+    for(let i = 0 ; i < list_a.length ; ++i) {
+      assert_approx_equals(list_a[i].x, list_b[i].x, 1.0);
+      assert_approx_equals(list_a[i].width, list_b[i].width, 1.0);
+      assert_approx_equals(list_a[i].height, list_b[i].height, 1.0);
+      // Y-position not tested here as getting the baseline for text in the
+      // DOM is not straightforward.
+    }
+  }
+
+  function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+    // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+    const LTR_OVERRIDE = '\u202D';
+    const RTL_OVERRIDE = '\u202E';
+    const OVERRIDE_END = '\u202C';
+    if (direction_is_ltr) {
+      return LTR_OVERRIDE + text + OVERRIDE_END;
+    }
+    return RTL_OVERRIDE + text + OVERRIDE_END;
+  }
+
+  ctx.font = '50px sans-serif';
+  ctx.direction = 'rtl';
+  ctx.textAlign = 'right';
+  ctx.letterSpacing = '10px';
+
+  const kTexts = [
+    'UNAVAILABLE',
+    '🏁🎶🏁',
+    '）（あ）（',
+    '-abcd_'
+  ]
+
+  for (text of kTexts) {
+    text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+    const tm = ctx.measureText(text);
+    // First character.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, 1),
+      placeAndSelectTextInDOM(text, 0, 1)
+    );
+    // Last character.
+    checkRectListsMatch(
+      tm.getSelectionRects(text.length - 1, text.length),
+      placeAndSelectTextInDOM(text, text.length - 1, text.length)
+    );
+    // Whole string.
+    checkRectListsMatch(
+      tm.getSelectionRects(0, text.length),
+      placeAndSelectTextInDOM(text, 0, text.length)
+    );
+    // Intermediate string.
+    checkRectListsMatch(
+      tm.getSelectionRects(1, text.length - 1),
+      placeAndSelectTextInDOM(text, 1, text.length - 1)
+    );
+    // Invalid start > end string. Creates 0 width rectangle.
+    checkRectListsMatch(
+      tm.getSelectionRects(3, 2),
+      placeAndSelectTextInDOM(text, 3, 2)
+    );
+    checkRectListsMatch(
+      tm.getSelectionRects(1, 0),
+      placeAndSelectTextInDOM(text, 1, 0)
+    );
+  }
+}, "Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with direction rtl, text align right, 10px letter spacing, and directional-override.");
 
-});
 </script>
diff --git a/tests/wpt/tests/html/canvas/tools/yaml-new/text.yaml b/tests/wpt/tests/html/canvas/tools/yaml-new/text.yaml
index 49edd754c85..240a04ce8dc 100644
--- a/tests/wpt/tests/html/canvas/tools/yaml-new/text.yaml
+++ b/tests/wpt/tests/html/canvas/tools/yaml-new/text.yaml
@@ -235,8 +235,9 @@
     @assert pixel 5,45 ==~ 0,255,0,255;
     @assert pixel 95,45 ==~ 0,255,0,255;
   expected: green
-  variants: &load-font-variant-definition
-  - HtmlCanvas:
+  variants:
+  - &load-font-variant-definition
+    HtmlCanvas:
       append_variants_to_name: false
       canvas_types: ['HtmlCanvas']
       load_font: |-
@@ -271,7 +272,8 @@
     @assert pixel 5,45 ==~ 0,255,0,255;
     @assert pixel 95,45 ==~ 0,255,0,255;
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.draw.baseline.middle
   desc: textBaseline middle is the middle of the em square (not the bounding box)
@@ -293,7 +295,8 @@
     @assert pixel 5,45 ==~ 0,255,0,255;
     @assert pixel 95,45 ==~ 0,255,0,255;
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.draw.baseline.alphabetic
   test_type: promise
@@ -314,7 +317,8 @@
     @assert pixel 5,45 ==~ 0,255,0,255;
     @assert pixel 95,45 ==~ 0,255,0,255;
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.draw.baseline.ideographic
   test_type: promise
@@ -335,7 +339,8 @@
     @assert pixel 5,45 ==~ 0,255,0,255; @moz-todo
     @assert pixel 95,45 ==~ 0,255,0,255; @moz-todo
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.draw.baseline.hanging
   test_type: promise
@@ -356,7 +361,8 @@
     @assert pixel 5,45 ==~ 0,255,0,255;
     @assert pixel 95,45 ==~ 0,255,0,255;
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.draw.space.collapse.space
   desc: Space characters are converted to U+0020, and are NOT collapsed
@@ -373,7 +379,8 @@
     @assert pixel 25,25 ==~ 0,255,0,255;
     @assert pixel 75,25 ==~ 255,0,0,255;
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.draw.space.collapse.other
   desc: Space characters are converted to U+0020, and are NOT collapsed
@@ -390,7 +397,8 @@
     @assert pixel 25,25 ==~ 0,255,0,255;
     @assert pixel 75,25 ==~ 255,0,0,255;
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.draw.space.collapse.start
   desc: Space characters at the start of a line are NOT collapsed
@@ -407,7 +415,8 @@
     @assert pixel 25,25 ==~ 255,0,0,255; @moz-todo
     @assert pixel 75,25 ==~ 0,255,0,255;
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.draw.space.collapse.end
   desc: Space characters at the end of a line are NOT collapsed
@@ -425,7 +434,8 @@
     @assert pixel 25,25 ==~ 0,255,0,255;
     @assert pixel 75,25 ==~ 255,0,0,255;
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.measure.width.space
   desc: Space characters are converted to U+0020 and NOT collapsed
@@ -442,7 +452,8 @@
 
     @assert ctx.measureText(' AB').width === 150;
     @assert ctx.measureText('AB ').width === 150;
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.drawing.style.measure.rtl.text
   desc: Measurement should follow canvas direction instead text direction
@@ -704,7 +715,8 @@
     @assert pixel 25,25 ==~ 0,255,0,255;
     @assert pixel 75,25 ==~ 0,255,0,255;
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.draw.fill.maxWidth.bound
   desc: fillText handles maxWidth based on line size, not bounding box size
@@ -723,7 +735,8 @@
     @assert pixel 25,25 ==~ 0,255,0,255;
     @assert pixel 75,25 ==~ 0,255,0,255;
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.draw.fontface
   fonts:
@@ -741,7 +754,8 @@
     @assert pixel 25,25 ==~ 0,255,0,255;
     @assert pixel 75,25 ==~ 0,255,0,255;
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.draw.fontface.repeat
   desc: Draw with the font immediately, then wait a bit until and draw again. (This
@@ -765,7 +779,8 @@
     _assertPixelApprox(canvas, 25,25, 0,255,0,255, 2);
     _assertPixelApprox(canvas, 75,25, 0,255,0,255, 2);
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.draw.fontface.notinpage
   desc: '@font-face fonts should work even if they are not used in the page'
@@ -785,7 +800,8 @@
     @assert pixel 25,25 ==~ 0,255,0,255; @moz-todo
     @assert pixel 75,25 ==~ 0,255,0,255; @moz-todo
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.draw.align.left
   desc: textAlign left is the left of the first em square (not the bounding box)
@@ -807,7 +823,8 @@
     @assert pixel 5,45 ==~ 0,255,0,255;
     @assert pixel 95,45 ==~ 0,255,0,255;
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.draw.align.right
   desc: textAlign right is the right of the last em square (not the bounding box)
@@ -829,7 +846,8 @@
     @assert pixel 5,45 ==~ 0,255,0,255;
     @assert pixel 95,45 ==~ 0,255,0,255;
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.draw.align.start.ltr
   desc: textAlign start with ltr is the left edge
@@ -855,7 +873,8 @@
     @assert pixel 5,45 ==~ 0,255,0,255;
     @assert pixel 95,45 ==~ 0,255,0,255;
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.draw.align.start.rtl
   desc: textAlign start with rtl is the right edge
@@ -881,7 +900,8 @@
     @assert pixel 5,45 ==~ 0,255,0,255;
     @assert pixel 95,45 ==~ 0,255,0,255;
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.draw.align.end.ltr
   desc: textAlign end with ltr is the right edge
@@ -907,7 +927,8 @@
     @assert pixel 5,45 ==~ 0,255,0,255;
     @assert pixel 95,45 ==~ 0,255,0,255;
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.draw.align.end.rtl
   desc: textAlign end with rtl is the left edge
@@ -933,7 +954,8 @@
     @assert pixel 5,45 ==~ 0,255,0,255;
     @assert pixel 95,45 ==~ 0,255,0,255;
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.draw.align.center
   desc: textAlign center is the center of the em squares (not the bounding box)
@@ -955,7 +977,8 @@
     @assert pixel 5,45 ==~ 0,255,0,255;
     @assert pixel 95,45 ==~ 0,255,0,255;
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 
 - name: 2d.text.draw.space.basic
@@ -973,7 +996,8 @@
     @assert pixel 25,25 ==~ 0,255,0,255;
     @assert pixel 75,25 ==~ 0,255,0,255;
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.draw.space.collapse.nonspace
   desc: Non-space characters are not converted to U+0020 and collapsed
@@ -990,7 +1014,8 @@
     @assert pixel 25,25 ==~ 0,255,0,255;
     @assert pixel 75,25 ==~ 0,255,0,255;
   expected: green
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.measure.width.basic
   desc: The width of character is same as font used
@@ -1006,7 +1031,8 @@
 
     ctx.font = '100px CanvasTest';
     @assert ctx.measureText('A').width === 100;
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.measure.width.empty
   desc: The empty string has zero width
@@ -1017,7 +1043,8 @@
     {{ load_font }}
     ctx.font = '50px CanvasTest';
     @assert ctx.measureText("").width === 0;
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.measure.actualBoundingBox
   desc: Testing actualBoundingBox
@@ -1052,7 +1079,8 @@
     @assert ctx.measureText('ABCD').actualBoundingBoxRight >= 200;
     @assert ctx.measureText('ABCD').actualBoundingBoxAscent >= 85;
     @assert ctx.measureText('ABCD').actualBoundingBoxDescent >= 37;
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.measure.fontBoundingBox
   desc: Testing fontBoundingBox measurements
@@ -1069,7 +1097,8 @@
 
     @assert ctx.measureText('ABCD').fontBoundingBoxAscent === 30;
     @assert ctx.measureText('ABCD').fontBoundingBoxDescent === 10;
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.measure.fontBoundingBox.ahem
   desc: Testing fontBoundingBox for font ahem
@@ -1085,7 +1114,8 @@
     @assert ctx.measureText('A').fontBoundingBoxDescent === 10;
     @assert ctx.measureText('ABCD').fontBoundingBoxAscent === 40;
     @assert ctx.measureText('ABCD').fontBoundingBoxDescent === 10;
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.measure.fontBoundingBox-reduced-ascent
   desc: Testing fontBoundingBox for OffscreenCanvas with reduced ascent metric
@@ -1102,7 +1132,8 @@
 
     @assert ctx.measureText('ABCD').fontBoundingBoxAscent === 10;
     @assert ctx.measureText('ABCD').fontBoundingBoxDescent === 10;
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.measure.fontBoundingBox-zero-descent
   desc: Testing fontBoundingBox for OffscreenCanvas with zero descent metric
@@ -1119,7 +1150,8 @@
 
     @assert ctx.measureText('ABCD').fontBoundingBoxAscent === 30;
     @assert ctx.measureText('ABCD').fontBoundingBoxDescent === 0;
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.measure.emHeights
   desc: Testing emHeights
@@ -1138,7 +1170,8 @@
     @assert ctx.measureText('ABCD').emHeightAscent === 30;
     @assert ctx.measureText('ABCD').emHeightDescent === 10;
     @assert ctx.measureText('ABCD').emHeightDescent + ctx.measureText('ABCD').emHeightAscent === 40;
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.measure.emHeights-low-ascent
   desc: Testing emHeights with reduced ascent metric
@@ -1157,7 +1190,8 @@
     @assert ctx.measureText('ABCD').emHeightAscent === 20;
     @assert ctx.measureText('ABCD').emHeightDescent === 20;
     @assert ctx.measureText('ABCD').emHeightDescent + ctx.measureText('ABCD').emHeightAscent === 40;
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.measure.emHeights-zero-descent
   desc: Testing emHeights with zero descent metric
@@ -1176,7 +1210,8 @@
     @assert ctx.measureText('ABCD').emHeightAscent === 40;
     @assert ctx.measureText('ABCD').emHeightDescent === 0;
     @assert ctx.measureText('ABCD').emHeightDescent + ctx.measureText('ABCD').emHeightAscent === 40;
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.measure.baselines
   desc: Testing baselines
@@ -1195,16 +1230,23 @@
     @assert Math.abs(ctx.measureText('ABCD').alphabeticBaseline) === 0;
     @assert ctx.measureText('ABCD').ideographicBaseline === 6.25;
     @assert ctx.measureText('ABCD').hangingBaseline === 25;
-  variants: *load-font-variant-definition
+  variants:
+  - *load-font-variant-definition
 
 - name: 2d.text.measure.selection-rects.tentative
-  desc: Check that TextMetrics::getSelectionRects() matches its DOM equivalent.
+  desc: >-
+    Check that TextMetrics::getSelectionRects() matches its DOM equivalent, with
+    direction {{ text_direction }}, text align {{ text_align }},
+    {{ letter_spacing }} letter spacing, and {{ variant_names[3] }}.
   canvas_types: ['HtmlCanvas', 'OffscreenCanvas']
   code: |
     function placeAndSelectTextInDOM(text, from, to) {
       const el = document.createElement("div");
       el.innerHTML = text;
       el.style.font = '50px sans-serif';
+      el.style.direction = '{{ text_direction }}';
+      el.style.textAlign = '{{ text_align }}';
+      el.style.letterSpacing = '{{ letter_spacing }}';
       document.body.appendChild(el);
 
       let range = document.createRange();
@@ -1212,6 +1254,10 @@
       range.setStart(el.childNodes[0], 0);
       range.setEnd(el.childNodes[0], text.length);
       const parent = range.getClientRects()[0];
+      let width = 0;
+      for (const rect of range.getClientRects()) {
+        width += rect.width;
+      }
 
       range.setStart(el.childNodes[0], from);
       range.setEnd(el.childNodes[0], to);
@@ -1224,8 +1270,21 @@
 
       document.body.removeChild(el);
 
+      // Offset to the alignment point determined by textAlign.
+      let text_align_dx;
+      switch (el.style.textAlign) {
+        case 'right':
+          text_align_dx = width;
+          break;
+        case 'center':
+          text_align_dx = width / 2;
+          break;
+        default:
+          text_align_dx = 0;
+      }
+
       for(let i = 0 ; i < sel_rects.length ; ++i) {
-        sel_rects[i].x -= parent.x;
+        sel_rects[i].x -= parent.x + text_align_dx;
         sel_rects[i].y -= parent.y;
       }
 
@@ -1242,16 +1301,36 @@
         // DOM is not straightforward.
       }
     }
+    {% if use_directional_override %}
+
+    function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+      // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+      const LTR_OVERRIDE = '\u202D';
+      const RTL_OVERRIDE = '\u202E';
+      const OVERRIDE_END = '\u202C';
+      if (direction_is_ltr) {
+        return LTR_OVERRIDE + text + OVERRIDE_END;
+      }
+      return RTL_OVERRIDE + text + OVERRIDE_END;
+    }
+    {% endif %}
 
     ctx.font = '50px sans-serif';
+    ctx.direction = '{{ text_direction }}';
+    ctx.textAlign = '{{ text_align }}';
+    ctx.letterSpacing = '{{ letter_spacing }}';
 
     const kTexts = [
       'UNAVAILABLE',
       '🏁🎶🏁',
-      '）（あ）（'
+      '）（あ）（',
+      '-abcd_'
     ]
 
-    for (const text of kTexts) {
+    for (text of kTexts) {
+      {% if use_directional_override %}
+      text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+      {% endif %}
       const tm = ctx.measureText(text);
       // First character.
       checkRectListsMatch(
@@ -1283,6 +1362,26 @@
         placeAndSelectTextInDOM(text, 1, 0)
       );
     }
+  variants_layout: [single_file, single_file, single_file, single_file]
+  variants:
+  - direction-ltr:
+      text_direction: ltr
+    direction-rtl:
+      text_direction: rtl
+  - align-left:
+      text_align: left
+    align-center:
+      text_align: center
+    align-right:
+      text_align: right
+  - no-spacing:
+      letter_spacing: 0px
+    spacing:
+      letter_spacing: 10px
+  - no-directional-override:
+      use_directional_override: false
+    directional-override:
+      use_directional_override: true
 
 - name: 2d.text.measure.selection-rects-baselines.tentative
   desc: >-
@@ -1303,7 +1402,8 @@
     const kTexts = [
       'UNAVAILABLE',
       '🏁🎶🏁',
-      '）（あ）（'
+      '）（あ）（',
+      '-abcd_'
     ]
 
     for (const text of kTexts) {
@@ -1349,7 +1449,8 @@
     const kTexts = [
       'UNAVAILABLE',
       '🏁🎶🏁',
-      '）（あ）（'
+      '）（あ）（',
+      '-abcd_'
     ]
 
     for (const text of kTexts) {
@@ -1367,6 +1468,478 @@
                         () => tm.getSelectionRects(text.length + 1, text.length + 1) );
     }
 
+- name: 2d.text.measure.getActualBoundingBox.tentative
+  desc: >-
+    Test TextMetrics::getActualBoundingBox(), with text align {{ text_align }}
+    , and {{ letter_spacing }} letter spacing.
+  test_type: promise
+  fonts:
+  - CanvasTest
+  size: [800, 200]
+  code: |
+    // Use measureText to create a rect for the whole text
+    function getFullTextBoundingBox(text) {
+      const tm = ctx.measureText(text);
+      return {
+        x: -tm.actualBoundingBoxLeft,
+        y: -tm.actualBoundingBoxAscent,
+        width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+        height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+      };
+    }
+
+    // Returns a string a replaces the characters in text that are not in the
+    // range [start, end) with spaces.
+    function buildTestString(text, start, end) {
+      let ret = '';
+      for (let i = 0; i < text.length; ++i) {
+        if (start <= i && i < end)
+          ret += text[i];
+        else
+          ret += ' ';
+      }
+      return ret;
+    }
+
+    function checkRectsMatch(rect_a, rect_b, text, start, end) {
+      assert_approx_equals(rect_a.x, rect_b.x, 1.0, `${text} :: x :: ${start} to ${end}`);
+      assert_approx_equals(rect_a.y, rect_b.y, 1.0, `${text} :: y :: ${start} to ${end}`);
+      assert_approx_equals(rect_a.width, rect_b.width, 1.0, `${text} :: width :: ${start} to ${end}`);
+      assert_approx_equals(rect_a.height, rect_b.height, 1.0, `${text} :: height :: ${start} to ${end}`);
+    }
+
+    function testForSubstring(text, start, end) {
+      const textMetrics = ctx.measureText(text);
+      const rect_from_api = textMetrics.getActualBoundingBox(start, end);
+      const rect_from_full_bounds = getFullTextBoundingBox(
+                                      buildTestString(text, start, end));
+      checkRectsMatch(rect_from_api, rect_from_full_bounds, buildTestString(text, start, end), start, end);
+    }
+
+    {{ load_font }}
+    ctx.textAlign = '{{ text_align }}';
+    ctx.letterSpacing = '{{ letter_spacing }}';
+
+    const kAligns = [
+      'left',
+      'center',
+      'right',
+    ];
+
+    const kBaselines = [
+      'top',
+      'hanging',
+      'middle',
+      'alphabetic',
+      'ideographic',
+      'bottom',
+    ];
+
+    ctx.font = '50px CanvasTest';
+    const text = 'ABCDE';
+    for (const align of kAligns) {
+      for (const baseline of kBaselines) {
+        ctx.textAlign = align;
+        ctx.textBaseline = baseline;
+        // Full string.
+        testForSubstring(text, 0, text.length);
+        // Intermediate string.
+        testForSubstring(text, 1, text.length - 1);
+        // First character.
+        testForSubstring(text, 0, 1);
+        // Intermediate character.
+        testForSubstring(text, 2, 3);
+      }
+    }
+  variants_layout:
+      [multi_files, single_file, single_file]
+  variants:
+  - *load-font-variant-definition
+  - align-left:
+      text_align: left
+    align-center:
+      text_align: center
+    align-right:
+      text_align: right
+  - no-spacing:
+      letter_spacing: 0px
+    spacing:
+      letter_spacing: 10px
+
+- name: 2d.text.measure.getActualBoundingBox-full-text.tentative
+  desc: >-
+    Test TextMetrics::getActualBoundingBox() for the full length of the string
+    for some edge cases, with direction {{ text_direction }} and
+    {{ variant_names[1] }}
+  size: [800, 200]
+  code: |
+    // Use measureText to create a rect for the whole text
+    function getFullTextBoundingBox(text) {
+      const tm = ctx.measureText(text);
+      return {
+        x: -tm.actualBoundingBoxLeft,
+        y: -tm.actualBoundingBoxAscent,
+        width: tm.actualBoundingBoxLeft + tm.actualBoundingBoxRight,
+        height: tm.actualBoundingBoxAscent + tm.actualBoundingBoxDescent
+      };
+    }
+
+    function checkRectsMatch(rect_a, rect_b) {
+      assert_approx_equals(rect_a.x, rect_b.x, 1.0);
+      assert_approx_equals(rect_a.y, rect_b.y, 1.0);
+      assert_approx_equals(rect_a.width, rect_b.width, 1.0);
+      assert_approx_equals(rect_a.height, rect_b.height, 1.0);
+    }
+    {% if use_directional_override %}
+
+    function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+      // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+      const LTR_OVERRIDE = '\u202D';
+      const RTL_OVERRIDE = '\u202E';
+      const OVERRIDE_END = '\u202C';
+      if (direction_is_ltr) {
+        return LTR_OVERRIDE + text + OVERRIDE_END;
+      }
+      return RTL_OVERRIDE + text + OVERRIDE_END;
+    }
+    {% endif %}
+
+    const kAligns = [
+      'left',
+      'center',
+      'right',
+    ];
+
+    const kBaselines = [
+      'top',
+      'hanging',
+      'middle',
+      'alphabetic',
+      'ideographic',
+      'bottom',
+    ];
+
+    const kTexts = [
+      'UNAVAILABLE',
+      '🏁🎶🏁',
+      '）（あ）（',
+      '-abcd '
+    ]
+
+    ctx.font = '50px sans-serif';
+    ctx.direction = '{{ text_direction }}';
+    for (const align of kAligns) {
+      for (const baseline of kBaselines) {
+        ctx.textAlign = align;
+        ctx.textBaseline = baseline;
+        for (text of kTexts) {
+          {% if use_directional_override %}
+          text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+          {% endif %}
+          const tm = ctx.measureText(text);
+          const rect_from_api = tm.getActualBoundingBox(0, text.length);
+          const rect_from_full_bounds = getFullTextBoundingBox(text);
+          checkRectsMatch(rect_from_api, rect_from_full_bounds)
+        }
+      }
+    }
+  variants_layout: [single_file, single_file]
+  variants:
+  - direction-ltr:
+      text_direction: ltr
+    direction-rtl:
+      text_direction: rtl
+  - no-directional-override:
+      use_directional_override: false
+    directional-override:
+      use_directional_override: true
+
+- name: 2d.text.measure.getActualBoundingBox-exceptions.tentative
+  desc: >-
+    Check that TextMetrics::getActualBoundingBox() throws when using invalid
+    indexes.
+  code: |
+    const kTexts = [
+      'UNAVAILABLE',
+      '🏁🎶🏁',
+      '）（あ）（',
+      '-abcd_'
+    ]
+
+    for (const text of kTexts) {
+      const tm = ctx.measureText(text);
+      // Handled by the IDL binding.
+      assert_throws_js(TypeError, () => tm.getActualBoundingBox(-1, 0) );
+      assert_throws_js(TypeError, () => tm.getActualBoundingBox(0, -1) );
+      assert_throws_js(TypeError, () => tm.getActualBoundingBox(-1, -1) );
+      // Thrown in TextMetrics.
+      assert_throws_dom("IndexSizeError",
+                        () => tm.getActualBoundingBox(text.length, 0) );
+      assert_throws_dom("IndexSizeError",
+                        () => tm.getActualBoundingBox(0, text.length + 1) );
+      assert_throws_dom("IndexSizeError",
+                        () => tm.getActualBoundingBox(text.length, text.length + 1) );
+
+- name: 2d.text.measure.caret-position.tentative
+  desc: >-
+    Check that TextMetrics::caretPositionFromPoint() matches its DOM equivalent,
+    where possible, with direction {{ text_direction }}, text align
+    {{ text_align }}, {{ letter_spacing }} letter spacing and
+    {{ variant_names[3] }}.
+  canvas_types: ['HtmlCanvas', 'OffscreenCanvas']
+  code: |
+    function alignOffset(offset, width) {
+      if ('{{ text_align }}' == 'center') {
+        offset -= width / 2;
+      } else if ('{{ text_align }}' == 'right' ||
+               ('{{ text_direction }}' == 'ltr' && '{{ text_align }}' == 'end') ||
+               ('{{ text_direction }}' == 'rtl' && '{{ text_align }}' == 'start')) {
+        offset -= width;
+      }
+      return offset;
+    }
+
+    {% if use_directional_override %}
+    function addDirectionalOverrideCharacters(text, direction_is_ltr) {
+      // source: www.w3.org/International/questions/qa-bidi-unicode-controls.en
+      const LTR_OVERRIDE = '\u202D';
+      const RTL_OVERRIDE = '\u202E';
+      const OVERRIDE_END = '\u202C';
+      if (direction_is_ltr) {
+        return LTR_OVERRIDE + text + OVERRIDE_END;
+      }
+      return RTL_OVERRIDE + text + OVERRIDE_END;
+    }
+    {% endif %}
+
+    function placeAndMeasureTextInDOM(text, text_width, point) {
+      const el = document.createElement("p");
+      el.innerHTML = text;
+      el.style.font = '50px sans-serif';
+      el.style.direction = '{{ text_direction }}';
+      el.style.letterSpacing = '{{ letter_spacing }}';
+      // Put the text top left to make offsets simpler.
+      el.style.padding = '0px';
+      el.style.margin = '0px';
+      el.style.position = 'absolute';
+      el.style.x = '0px';
+      el.style.y = '0px';
+      document.body.appendChild(el);
+      text_bound = el.getBoundingClientRect();
+      text_x = text_bound.x;
+      text_y = text_bound.y + text_bound.height / 2;
+
+      // Offset to the requested point determined by textAlign and direction.
+      let text_align_dx = 0;
+      if ('{{ text_align }}' == 'center') {
+        text_align_dx = text_width / 2;
+      } else if ('{{ text_align }}' == 'right' ||
+               ('{{ text_direction }}' == 'ltr' && '{{ text_align }}' == 'end') ||
+               ('{{ text_direction }}' == 'rtl' && '{{ text_align }}' == 'start')) {
+        text_align_dx = text_width;
+      }
+      position = document.caretPositionFromPoint(point + text_align_dx + text_x, text_y);
+      @assert position.offsetNode.parentNode === el;
+
+      document.body.removeChild(el);
+
+      return position.offset;
+    }
+
+    ctx.font = '50px sans-serif';
+    ctx.direction = '{{ text_direction }}';
+    ctx.textAlign = '{{ text_align }}';
+    ctx.letterSpacing = '{{ letter_spacing }}';
+
+    const kTexts = [
+      'UNAVAILABLE',
+      '🏁🎶🏁',
+      '）（あ）（',
+      '--abcd__'
+    ]
+
+    for (text of kTexts) {
+      {% if use_directional_override %}
+      text = addDirectionalOverrideCharacters(text, ctx.direction == 'ltr');
+      {% endif %}
+      const tm = ctx.measureText(text);
+      text_width = tm.width;
+      step = 30;
+      if ('{{letter_spacing}}' == '10px') {
+        step = 40;
+      }
+
+      offset = step;
+      adjusted_offset = alignOffset(offset, text_width);
+      tm_position = tm.caretPositionFromPoint(adjusted_offset);
+      doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+      assert_equals(tm_position,
+                    doc_position,
+                    "for " + text + " offset " + offset);
+
+      offset = text_width / 2;
+      adjusted_offset = alignOffset(offset, text_width);
+      tm_position = tm.caretPositionFromPoint(adjusted_offset);
+      doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+      assert_equals(tm_position,
+                    doc_position,
+                    "for " + text + " offset " + offset);
+
+      offset = text_width - step;
+      adjusted_offset = alignOffset(offset, text_width);
+      tm_position = tm.caretPositionFromPoint(adjusted_offset);
+      doc_position = placeAndMeasureTextInDOM(text, text_width, adjusted_offset);
+      assert_equals(tm_position,
+                    doc_position,
+                    "for " + text + " offset " + offset);
+    }
+  variants_layout: [single_file, single_file, single_file, single_file]
+  variants:
+  - direction-ltr:
+      text_direction: ltr
+    direction-rtl:
+      text_direction: rtl
+  - align-left:
+      text_align: left
+    align-center:
+      text_align: center
+    align-right:
+      text_align: right
+    align-start:
+      text_align: start
+    align-end:
+      text_align: end
+  - no-spacing:
+      letter_spacing: 0px
+    spacing:
+      letter_spacing: 10px
+  - no-directional-override:
+      use_directional_override: false
+    directional-override:
+      use_directional_override: true
+
+- name: 2d.text.measure.caret-position-edges.tentative
+  desc: >-
+    Check that TextMetrics::caretPositionFromPoint() gives correct edges when
+    the requested point is outside the range, with direction {{ text_direction }}
+    and text align {{ text_align }}.
+  code: |
+    function computeExpected(text, text_width, offset) {
+      expected_position = 0;
+      if ('{{ text_align }}' == 'center' && offset == 0) {
+        return text.length / 2;
+      }
+      if ('{{ text_direction }}' == 'ltr') {
+        if (offset >= text_width) {
+          return text.length;
+        }
+        if (offset <= -text_width) {
+          return 0;
+        }
+        // offset must be 0.
+        if ('{{ text_align }}' == 'start' || '{{ text_align }}' == 'left') {
+          return 0;
+        } else {
+          return text.length;
+        }
+      } else {
+        if (offset >= text_width) {
+          return 0;
+        }
+        if (offset <= -text_width) {
+          return text.length;
+        }
+        // offset must be 0.
+        if ('{{ text_align }}' == 'start' || '{{ text_align }}' == 'right') {
+          return 0;
+        } else {
+          return text.length;
+        }
+      }
+      return expected_position;
+    }
+
+    ctx.font = '50px sans-serif';
+    ctx.direction = '{{ text_direction }}';
+    ctx.textAlign = '{{ text_align }}';
+    ctx.letterSpacing = '{{ letter_spacing }}';
+
+    // The leading and trailing '-' cause the string to always follow
+    // the specified direction, even though the interior will always be ltr.
+    const text = '-0123456789-';
+
+    // Points are multiples of the string width as reported by
+    // textMetrics.width.
+    const kPoints = [
+      -2,
+      -1,
+      0,
+      1,
+      2
+    ]
+
+    const tm = ctx.measureText(text);
+    text_width = tm.width;
+    for (const multiple of kPoints) {
+      offset = multiple * text_width;
+      tm_position = tm.caretPositionFromPoint(offset);
+      expected_position = computeExpected(text, text_width, offset);
+      assert_equals(tm_position,
+                    expected_position,
+                    "for " + text + " multiple " + multiple);
+    }
+  variants_layout: [single_file, single_file]
+  variants:
+  - direction-ltr:
+      text_direction: ltr
+    direction-rtl:
+      text_direction: rtl
+  - align-left:
+      text_align: left
+    align-center:
+      text_align: center
+    align-right:
+      text_align: right
+    align-start:
+      text_align: start
+    align-end:
+      text_align: end
+
+- name: 2d.text.measure.caret-position-edge-cases.tentative
+  desc: >-
+    Test the edge cases for caretPositionFromPoint, where the point is at the
+    edge of glyph and at the midpoint.
+  test_type: promise
+  fonts:
+  - CanvasTest
+  code: |
+    {{ load_font }}
+    ctx.font = '50px CanvasTest';
+    ctx.direction = 'ltr';
+    ctx.align = 'left'
+    ctx.baseline = 'alphabetic'
+    tm = ctx.measureText('A');
+    const a_width = tm.width;
+    tm = ctx.measureText('B');
+    const b_width = tm.width;
+    tm = ctx.measureText('C');
+    const c_width = tm.width;
+    const epsilon = 1.0e-4;
+
+    tm = ctx.measureText('ABC');
+    @assert tm.caretPositionFromPoint(0) == 0;
+    @assert tm.caretPositionFromPoint(a_width / 2) == 0;
+    @assert tm.caretPositionFromPoint(a_width / 2 + 1) == 1;
+    @assert tm.caretPositionFromPoint(a_width) == 1;
+    @assert tm.caretPositionFromPoint(a_width + b_width / 2) == 1;
+    @assert tm.caretPositionFromPoint(a_width + b_width / 2 + 1) == 2;
+    @assert tm.caretPositionFromPoint(a_width + b_width) == 2;
+    @assert tm.caretPositionFromPoint(a_width + b_width + c_width / 2) == 2;
+    @assert tm.caretPositionFromPoint(a_width + b_width + c_width / 2 + 1) == 3;
+    @assert tm.caretPositionFromPoint(a_width + b_width + c_width) == 3;
+  variants:
+  - *load-font-variant-definition
+
 - name: 2d.text.drawing.style.absolute.spacing
   desc: Testing letter spacing and word spacing with absolute length
   code: |
diff --git a/tests/wpt/tests/html/cross-origin-opener-policy/reporting/resources/reporting-common.js b/tests/wpt/tests/html/cross-origin-opener-policy/reporting/resources/reporting-common.js
index 70bb4897f50..accb6faaec5 100644
--- a/tests/wpt/tests/html/cross-origin-opener-policy/reporting/resources/reporting-common.js
+++ b/tests/wpt/tests/html/cross-origin-opener-policy/reporting/resources/reporting-common.js
@@ -378,6 +378,8 @@ const coopHeaders = function (uuid) {
         getHeader(uuid, "same-origin-allow-popups", is_report_only = true),
     coopReportOnlyRestrictPropertiesHeader:
         getHeader(uuid, "restrict-properties", is_report_only = true),
+    coopReportOnlyNoopenerAllowPopupsHeader:
+        getHeader(uuid, "noopener-allow-popups", is_report_only = true),
   };
 }
 
diff --git a/tests/wpt/tests/html/cross-origin-opener-policy/reporting/tentative/access-to-noopener-page-from-no-coop-ro.https.html b/tests/wpt/tests/html/cross-origin-opener-policy/reporting/tentative/access-to-noopener-page-from-no-coop-ro.https.html
new file mode 100644
index 00000000000..5e407de3482
--- /dev/null
+++ b/tests/wpt/tests/html/cross-origin-opener-policy/reporting/tentative/access-to-noopener-page-from-no-coop-ro.https.html
@@ -0,0 +1,69 @@
+<!DOCTYPE html>
+<title>
+  COOP reports are sent when the openee used COOP-RO+COEP and then its
+  same-origin opener tries to access it.
+</title>
+<meta name=timeout content=long>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src=/common/get-host-info.sub.js></script>
+<script src="/common/utils.js"></script>
+<script src="/common/dispatcher/dispatcher.js"></script>
+<script src="/html/cross-origin-opener-policy/reporting/resources/reporting-common.js"></script>
+<script src="/html/cross-origin-opener-policy/reporting/resources/try-access.js"></script>
+<script>
+
+const directory = "/html/cross-origin-opener-policy";
+const redirect_path = directory + "/resources/redirect.py?";
+const same_origin = get_host_info().HTTPS_ORIGIN;
+
+let runTest = (openee_redirect, name) => promise_test(async t => {
+  const report_token = token();
+  const openee_token = token();
+  const opener_token = token(); // The current test window.
+
+  const opener_url = location.href;
+
+  const reportTo = reportToHeaders(report_token);
+  const openee_url = same_origin + executor_path + reportTo.header +
+    reportTo.coopReportOnlyNoopenerAllowPopupsHeader + coep_header +
+    `&uuid=${openee_token}`;
+  const openee_redirect_url = same_origin + redirect_path + openee_url
+  const openee_requested_url = openee_redirect ? openee_redirect_url
+                                               : openee_url;
+
+
+  const openee = window.open(openee_requested_url);
+  t.add_cleanup(() => send(openee_token, "window.close()"))
+
+  // 1. Make sure the new document to be loaded.
+  send(openee_token, `
+    send("${opener_token}", "Ready");
+  `);
+  let reply = await receive(opener_token);
+  assert_equals(reply, "Ready");
+
+  // 2. Try to access the openee. A report is sent, because of COOP-RO+COEP.
+  tryAccess(openee);
+
+  // 3. Check a report is sent to the openee.
+  let report =
+    await receiveReport(report_token, "access-to-coop-page-from-opener")
+  assert_equals(report.type, "coop");
+  assert_equals(report.url, openee_url.replace(/"/g, '%22'));
+  assert_equals(report.body.disposition, "reporting");
+  assert_equals(report.body.effectivePolicy, "noopener-allow-popups");
+  assert_equals(report.body.property, "blur");
+  assert_source_location_missing(report);
+  assert_equals(report.body.openerURL, opener_url);
+  assert_equals(report.body.openeeURL, undefined);
+  assert_equals(report.body.otherDocumentURL, undefined);
+  assert_equals(report.body.referrer, opener_url);
+  assert_equals(report.body.initialPopupURL, undefined);
+}, name);
+
+runTest(false, "access-to-coop-page-from-opener, noopener-allow-popups");
+runTest(true , "access-to-coop-page-from-opener, noopener-allow-popups + redirect");
+
+</script>
+
diff --git a/tests/wpt/tests/html/cross-origin-opener-policy/resources/noopener-helper.js b/tests/wpt/tests/html/cross-origin-opener-policy/resources/noopener-helper.js
new file mode 100644
index 00000000000..1f9b0775071
--- /dev/null
+++ b/tests/wpt/tests/html/cross-origin-opener-policy/resources/noopener-helper.js
@@ -0,0 +1,163 @@
+const executor_path = '/common/dispatcher/executor.html?pipe=';
+const coop_header = policy => {
+  return `|header(Cross-Origin-Opener-Policy,${policy})`;
+};
+
+function getExecutorPath(uuid, origin, coop_header) {
+  return origin.origin + executor_path + coop_header + `&uuid=${uuid}`;
+}
+
+// Open a same-origin popup with `opener_coop` header, then open a popup with
+// `openee_coop` header. Check whether the opener can script the openee.
+const test_noopener_opening_popup = (
+  opener_coop,
+  openee_coop,
+  opener_expectation
+) => {
+  promise_test(async t => {
+    // Set up dispatcher communications.
+    const popup_token = token();
+    const reply_token = token();
+    const popup_reply_token = token();
+    const popup_openee_token = token();
+
+    const popup_url = getExecutorPath(
+      popup_token, SAME_ORIGIN, coop_header(opener_coop));
+
+    // We open a popup and then ping it, it will respond after loading.
+    const popup = window.open(popup_url);
+    t.add_cleanup(() => send(popup_token, 'window.close()'));
+    send(popup_token, `send('${reply_token}', 'Popup loaded');`);
+    assert_equals(await receive(reply_token), 'Popup loaded');
+
+    if (opener_coop == 'noopener-allow-popups') {
+      // Assert that we can't script the popup.
+      await t.step_wait(() => popup.closed, 'Opener popup.closed')
+    }
+
+    // Ensure that the popup has no access to its opener.
+    send(popup_token, `
+      let openerDOMAccessAllowed = false;
+      try {
+        openerDOMAccessAllowed = !!self.opener.document.URL;
+      } catch(ex) {}
+      const payload = {
+        opener: !!self.opener,
+        openerDOMAccess: openerDOMAccessAllowed
+      };
+      send('${reply_token}', JSON.stringify(payload));
+    `);
+    let payload = JSON.parse(await receive(reply_token));
+    if (opener_coop == 'noopener-allow-popups') {
+      assert_false(payload.opener, 'popup opener');
+      assert_false(payload.openerDOMAccess, 'popup DOM access');
+    }
+
+    // Open another popup from inside the popup, and wait for it to load.
+    const popup_openee_url = getExecutorPath(popup_openee_token, SAME_ORIGIN,
+      coop_header(openee_coop));
+    send(popup_token, `
+      window.openee = open("${popup_openee_url}");
+      await receive('${popup_reply_token}');
+      const payload = {
+        openee: !!window.openee,
+        closed: window.openee.closed
+      };
+      send('${reply_token}', JSON.stringify(payload));
+    `);
+    t.add_cleanup(() => send(popup_token, 'window.openee.close()'));
+    // Notify the popup that its openee was loaded.
+    send(popup_openee_token, `
+      send('${popup_reply_token}', 'popup openee opened');
+    `);
+
+    // Assert that the popup has access to its openee.
+    payload = JSON.parse(await receive(reply_token));
+    assert_true(payload.openee, 'popup openee');
+
+    // Assert that the openee has access to its popup opener.
+    send(popup_openee_token, `
+      let openerDOMAccessAllowed = false;
+      try {
+        openerDOMAccessAllowed = !!self.opener.document.URL;
+      } catch(ex) {}
+      const payload = {
+        opener: !!self.opener,
+        openerDOMAccess: openerDOMAccessAllowed
+      };
+      send('${reply_token}', JSON.stringify(payload));
+    `);
+    payload = JSON.parse(await receive(reply_token));
+    if (opener_expectation) {
+      assert_true(payload.opener, 'Opener is not null');
+      assert_true(payload.openerDOMAccess, 'No DOM access');
+    } else {
+      assert_false(payload.opener, 'Opener is null');
+      assert_false(payload.openerDOMAccess, 'No DOM access');
+    }
+  },
+  'noopener-allow-popups ensures that the opener cannot script the openee,' +
+  ' but further popups with no COOP can access their opener: ' +
+  opener_coop + '/' + openee_coop);
+};
+
+// Open a same-origin popup with `popup_coop` header, then navigate away toward
+// one with `noopener-allow-popups`. Check the opener can't script the openee.
+const test_noopener_navigating_away = (popup_coop) => {
+  promise_test(async t => {
+    // Set up dispatcher communications.
+    const popup_token = token();
+    const reply_token = token();
+    const popup_reply_token = token();
+    const popup_second_token = token();
+
+    const popup_url =
+      getExecutorPath(popup_token, SAME_ORIGIN, coop_header(popup_coop));
+
+    // We open a popup and then ping it, it will respond after loading.
+    const popup = window.open(popup_url);
+    send(popup_token, `send('${reply_token}', 'Popup loaded');`);
+    assert_equals(await receive(reply_token), 'Popup loaded');
+    t.add_cleanup(() => send(popup_token, 'window.close()'));
+
+    // Assert that we can script the popup.
+    assert_not_equals(popup.window, null);
+    assert_false(popup.closed, 'popup closed');
+
+    // Ensure that the popup has no access to its opener.
+    send(popup_token, `
+      let openerDOMAccessAllowed = false;
+      try {
+        openerDOMAccessAllowed = !!self.opener.document.URL;
+      } catch(ex) {}
+      const payload = {
+        opener: !!self.opener,
+        openerDOMAccess: openerDOMAccessAllowed
+      };
+      send('${reply_token}', JSON.stringify(payload));
+    `);
+    let payload = JSON.parse(await receive(reply_token));
+    assert_true(payload.opener, 'popup opener');
+    assert_true(payload.openerDOMAccess, 'popup DOM access');
+
+    // Navigate the popup.
+    const popup_second_url = getExecutorPath(
+      popup_second_token, SAME_ORIGIN,
+      coop_header('noopener-allow-popups'));
+
+    send(popup_token, `
+      window.location = '${popup_second_url}';
+    `);
+
+    // Notify the popup that its openee was loaded.
+    send(popup_second_token, `
+      send('${reply_token}', 'popup navigated away');
+    `);
+    assert_equals(await receive(reply_token), 'popup navigated away');
+
+    assert_equals(popup.window, null);
+    assert_true(popup.closed, 'popup.closed');
+  },
+  'noopener-allow-popups ensures that the opener cannot script the openee,' +
+  ' even after a navigation: ' + popup_coop);
+};
diff --git a/tests/wpt/tests/html/cross-origin-opener-policy/tentative/noopener/coop-noopener-allow-popups-restrict-properties.https.html b/tests/wpt/tests/html/cross-origin-opener-policy/tentative/noopener/coop-noopener-allow-popups-restrict-properties.https.html
new file mode 100644
index 00000000000..3058011c088
--- /dev/null
+++ b/tests/wpt/tests/html/cross-origin-opener-policy/tentative/noopener/coop-noopener-allow-popups-restrict-properties.https.html
@@ -0,0 +1,24 @@
+<!doctype html>
+<meta name="timeout" content="long">
+<title>
+    Cross-Origin-Opener-Policy: noopener-allow-popups means that the opener
+    has no access to the openee. This test verfies it for restrict-properties
+    COOP values.
+</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/dispatcher/dispatcher.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="/common/utils.js"></script>
+<script src="../../resources/common.js"></script>
+<script src="../../resources/noopener-helper.js"></script>
+<script>
+
+
+test_noopener_opening_popup("noopener-allow-popups",
+                            "restrict-properties",
+                            /*opener_expectation=*/true);
+test_noopener_opening_popup("restrict-properties",
+                            "noopener-allow-popups",
+                            /*opener_expectation=*/false);
+ </script>
diff --git a/tests/wpt/tests/html/cross-origin-opener-policy/tentative/noopener/coop-noopener-allow-popups.https.html b/tests/wpt/tests/html/cross-origin-opener-policy/tentative/noopener/coop-noopener-allow-popups.https.html
new file mode 100644
index 00000000000..0daf3278476
--- /dev/null
+++ b/tests/wpt/tests/html/cross-origin-opener-policy/tentative/noopener/coop-noopener-allow-popups.https.html
@@ -0,0 +1,36 @@
+<!doctype html>
+<meta name="timeout" content="long">
+<title>
+    Cross-Origin-Opener-Policy: noopener-allow-popups means that the opener
+    has no access to the openee.
+</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/dispatcher/dispatcher.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="/common/utils.js"></script>
+<script src="../../resources/common.js"></script>
+<script src="../../resources/noopener-helper.js"></script>
+<script>
+
+
+test_noopener_opening_popup("noopener-allow-popups",
+                            "unsafe-none",
+                            /*opener_expectation=*/true);
+test_noopener_opening_popup("noopener-allow-popups",
+                            "noopener-allow-popups",
+                            /*opener_expectation=*/false);
+test_noopener_opening_popup("noopener-allow-popups",
+                            "same-origin",
+                            /*opener_expectation=*/false);
+test_noopener_opening_popup("noopener-allow-popups",
+                            "same-origin-allow-popups",
+                            /*opener_expectation=*/true);
+test_noopener_opening_popup("same-origin-allow-popups",
+                            "noopener-allow-popups",
+                            /*opener_expectation=*/false);
+test_noopener_opening_popup("same-origin",
+                            "noopener-allow-popups",
+                            /*opener_expectation=*/false);
+test_noopener_navigating_away("unsafe-none");
+ </script>
diff --git a/tests/wpt/tests/html/dom/elements/global-attributes/cdata-dir_auto.html b/tests/wpt/tests/html/dom/elements/global-attributes/cdata-dir_auto.html
new file mode 100644
index 00000000000..91231f7e6c6
--- /dev/null
+++ b/tests/wpt/tests/html/dom/elements/global-attributes/cdata-dir_auto.html
@@ -0,0 +1,71 @@
+<!DOCTYPE html>
+<head>
+    <meta charset="utf-8">
+    <link rel="author" title="Vincent Hilla" href="mailto:vhilla@mozilla.com">
+    <link rel="help" href="https://html.spec.whatwg.org/multipage/dom.html#the-directionality">
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+    <div id="test1" dir="auto">
+        <![CDATA[foo]]>اختبر
+    </div>
+
+    <iframe src="cdata-iframe.xhtml"></iframe>
+
+    <script>
+        function awaitMessage(msg) {
+            return new Promise(res => {
+                function waitAndRemove(e) {
+                    if (e.data != msg)
+                        return;
+                    window.removeEventListener("message", waitAndRemove);
+                    res();
+                }
+                window.addEventListener("message", waitAndRemove);
+            });
+        }
+
+        const subframeLoaded = awaitMessage("subframe-loaded");
+
+        async function createXHTMLCase(id) {
+            await subframeLoaded;
+
+            let iframe = document.querySelector("iframe");
+            iframe.contentWindow.postMessage(id, "*");
+
+            await awaitMessage(id);
+
+            const doc = iframe.contentDocument;
+            const div = doc.getElementById(id);
+            const cdata = div.firstChild;
+
+            return [div, cdata];
+        }
+
+        test(function() {
+            const div = document.getElementById("test1");
+            assert_true(div.matches(":dir(rtl)"));
+        }, "Content of CDATA is ignored for dir=auto in html document");
+
+        promise_test(async function() {
+            let [div, cdata] = await createXHTMLCase(1);
+            assert_true(div.matches(":dir(ltr)"));
+        }, "Text in CDATASection is considered when determining auto directionality");
+
+        promise_test(async function() {
+            let [div, cdata] = await createXHTMLCase(2);
+            assert_true(div.matches(":dir(ltr)"));
+            cdata.remove();
+            assert_true(div.matches(":dir(rtl)"));
+        }, "Directionality is updated when removing CDATASection");
+
+        promise_test(async function() {
+            let [div, cdata] = await createXHTMLCase(3);
+            assert_true(div.matches(":dir(ltr)"));
+            cdata.textContent = "اختبر";
+            assert_true(div.matches(":dir(rtl)"));
+        }, "Directionality is updated when changing text of CDATASection");
+    </script>
+</body>
+</html>
diff --git a/tests/wpt/tests/html/dom/elements/global-attributes/cdata-iframe.xhtml b/tests/wpt/tests/html/dom/elements/global-attributes/cdata-iframe.xhtml
new file mode 100644
index 00000000000..0c48cbef4fc
--- /dev/null
+++ b/tests/wpt/tests/html/dom/elements/global-attributes/cdata-iframe.xhtml
@@ -0,0 +1,32 @@
+<?xml version="1.0"?>
+<html xmlns="http://www.w3.org/1999/xhtml">
+    <body>
+        <div id="container"></div>
+    </body>
+
+    <script>
+        function createXHTMLCase(id) {
+            const container = document.getElementById("container");
+
+            const div = document.createElement("div");
+            div.dir = "auto";
+            div.id = id;
+
+            const cdata = document.createCDATASection("foo");
+            const text = document.createTextNode("اختبر");
+            div.appendChild(cdata);
+            div.appendChild(text);
+
+            container.appendChild(div);
+
+            return [div, cdata];
+        }
+
+        window.addEventListener("message", (e) => {
+            createXHTMLCase(e.data);
+            window.top.postMessage(e.data);
+        });
+
+        window.top.postMessage("subframe-loaded");
+    </script>
+</html>
diff --git a/tests/wpt/tests/html/dom/elements/global-attributes/dir-assorted.window.js b/tests/wpt/tests/html/dom/elements/global-attributes/dir-assorted.window.js
index 93f798e6002..3bd63e2ae05 100644
--- a/tests/wpt/tests/html/dom/elements/global-attributes/dir-assorted.window.js
+++ b/tests/wpt/tests/html/dom/elements/global-attributes/dir-assorted.window.js
@@ -97,22 +97,24 @@ for (const tag of ["style", "script", "input", "textarea"]) {
   }, `non-html ${tag} element text contents influence dir=auto`);
 }
 
-test(() => {
-  const e1 = document.createElement("div");
-  e1.dir = "auto";
-  const e2 = document.createElement("div");
-  e2.dir = "auto";
-  e2.innerText = "A";
-  e1.append(e2);
-  assert_true(e1.matches(":dir(ltr)"), "parent is LTR before changes");
-  assert_true(e2.matches(":dir(ltr)"), "child is LTR before changes");
-  e2.removeAttribute("dir");
-  assert_true(e1.matches(":dir(ltr)"), "parent is LTR after removing dir attribute on child");
-  assert_true(e2.matches(":dir(ltr)"), "child is LTR after removing dir attribute on child");
-  e2.firstChild.data = "\u05D0";
-  assert_false(e1.matches(":dir(ltr)"), "parent is RTL after changing text in child");
-  assert_false(e2.matches(":dir(ltr)"), "child is RTL after changing text in child");
-}, "text changes apply to dir=auto on further ancestor after removing dir=auto from closer ancestor");
+for (const dir of ["auto", "ltr"]) {
+  test(() => {
+    const e1 = document.createElement("div");
+    e1.dir = "auto";
+    const e2 = document.createElement("div");
+    e2.dir = dir;
+    e2.innerText = "A";
+    e1.append(e2);
+    assert_true(e1.matches(":dir(ltr)"), "parent is LTR before changes");
+    assert_true(e2.matches(":dir(ltr)"), "child is LTR before changes");
+    e2.removeAttribute("dir");
+    assert_true(e1.matches(":dir(ltr)"), "parent is LTR after removing dir attribute on child");
+    assert_true(e2.matches(":dir(ltr)"), "child is LTR after removing dir attribute on child");
+    e2.firstChild.data = "\u05D0";
+    assert_false(e1.matches(":dir(ltr)"), "parent is RTL after changing text in child");
+    assert_false(e2.matches(":dir(ltr)"), "child is RTL after changing text in child");
+  }, `text changes apply to dir=auto on further ancestor after removing dir=${dir} from closer ancestor`);
+}
 
 for (const bdi_test of [
   { markup: "<bdi dir=ltr>A</bdi>", expected: "ltr", desc: "dir=ltr with LTR contents" },
diff --git a/tests/wpt/tests/html/dom/elements/global-attributes/dir-auto-dynamic-changes.window.js b/tests/wpt/tests/html/dom/elements/global-attributes/dir-auto-dynamic-changes.window.js
index a0cf4aae7ba..d57d8664dfa 100644
--- a/tests/wpt/tests/html/dom/elements/global-attributes/dir-auto-dynamic-changes.window.js
+++ b/tests/wpt/tests/html/dom/elements/global-attributes/dir-auto-dynamic-changes.window.js
@@ -1,18 +1,4 @@
-function setup_tree(light_tree, shadow_tree) {
-  let body = document.body;
-  let old_length = body.childNodes.length;
-  body.insertAdjacentHTML("beforeend", light_tree.trim());
-  if (body.childNodes.length != old_length + 1) {
-    throw "unexpected markup";
-  }
-  let result = body.lastChild;
-  if (shadow_tree) {
-    let shadow = result.querySelector("#root").attachShadow({mode: "open"});
-    shadow.innerHTML = shadow_tree.trim();
-    return [result, shadow];
-  }
-  return result;
-}
+// META: script=dir-shadow-utils.js
 
 test(t => {
   let a = setup_tree(`
@@ -55,8 +41,7 @@ test(() => {
 }, "dir=auto changes for content insertion and removal, in and out of document");
 
 test(() => {
-  let tree, shadow;
-  [tree, shadow] = setup_tree(`
+  let [tree, shadow] = setup_tree(`
     <div>
       <div id="root">
         <span id="l">A</span>
@@ -88,8 +73,7 @@ test(() => {
 }, "dir=auto changes for slot reassignment");
 
 test(() => {
-  let tree, shadow;
-  [tree, shadow] = setup_tree(`
+  let [tree, shadow] = setup_tree(`
     <div dir=auto>
       <div id=root>
         <div id=text>A</div>
@@ -195,8 +179,7 @@ test(() => {
 }, "dynamic changes inside of non-HTML elements");
 
 test(() => {
-  let tree, shadow;
-  [tree, shadow] = setup_tree(`
+  let [tree, shadow] = setup_tree(`
     <div dir="auto">
       <div id="root">
         <element xmlns="namespace">A</element>
@@ -233,8 +216,7 @@ test(() => {
 }, "slotted non-HTML elements");
 
 test(() => {
-  let tree, shadow;
-  [tree, shadow] = setup_tree(`
+  let [tree, shadow] = setup_tree(`
     <div>
       <div id="root">
         <!-- element goes here -->
@@ -274,3 +256,171 @@ test(() => {
 
   tree.remove();
 }, "slotted non-HTML elements after dynamically assigning dir=auto, and dir attribute ignored on non-HTML elements");
+
+test(() => {
+  let e1 = setup_tree(`
+    <div dir=auto>
+      <div dir=ltr>
+        \u05D0
+      </div>
+    </div>
+  `);
+  let e2 = e1.firstElementChild;
+  assert_true(e1.matches(":dir(ltr)"), "parent is LTR before changes");
+  assert_true(e2.matches(":dir(ltr)"), "child is LTR before changes");
+  e2.removeAttribute("dir");
+  assert_false(e1.matches(":dir(ltr)"), "parent is RTL after removing dir from child");
+  assert_false(e2.matches(":dir(ltr)"), "child is RTL after removing dir from child");
+}, "dir=auto ancestor considers text in subtree after removing dir=ltr from it");
+
+test(() => {
+  let tree1, shadow1;
+  [tree1, shadow1] = setup_tree(`
+    <div>
+      <div id="root" dir="auto">
+        <div id="root2">
+          <span>A</span>
+        </div>
+      </div>
+    </div>
+  `,`
+    <slot dir="auto"></slot>
+  `);
+  let tree2 = tree1.querySelector("#root2");
+  let shadow2 = tree2.attachShadow({mode: 'open'});
+  shadow2.innerHTML = '<slot dir="auto"></slot>';
+
+  let slot1 = shadow1.querySelector("slot");
+  let slot2 = shadow2.querySelector("slot");
+  let span = tree1.querySelector("span");
+
+  // span slotted in slot2 hosted in root2 slotted in slot1
+  // span thus impacts auto-dir of two slots
+  assert_true(slot1.matches(":dir(ltr)", "outer slot initially ltr"));
+  assert_true(slot2.matches(":dir(ltr)", "inner slot initially ltr"));
+  span.innerHTML = "\u05D0";
+  assert_true(slot1.matches(":dir(rtl)", "outer slot changed to rtl"));
+  assert_true(slot2.matches(":dir(rtl)", "inner slot changed to rtl"));
+
+  tree1.remove();
+}, 'Slotted content affects multiple dir=auto slots');
+
+test(() => {
+  let [tree, shadow] = setup_tree(`
+    <div>
+      <div id="root">
+        <span>اختبر</span>
+      </div>
+    </div>
+  `, `
+    <slot dir="auto"></slot>
+  `);
+
+  let slot = shadow.querySelector("slot");
+  assert_equals(html_direction(slot), "rtl", "slot initially rtl");
+  let span = tree.querySelector("span");
+  span.remove();
+  assert_equals(html_direction(slot), "ltr", "slot is reset to ltr");
+  tree.remove();
+}, 'Removing slotted content resets direction on dir=auto slot');
+
+test(() => {
+  let [tree, shadow] = setup_tree(`
+    <div>
+      <div id=root>
+        <div>
+          <span>اختبر</span>
+        </div>
+      </div>
+    </div>
+  `,`
+    <slot dir=auto></slot>
+  `);
+
+  let slot = shadow.querySelector("slot");
+  assert_equals(html_direction(slot), "rtl", "slot initially rtl");
+  let span = tree.querySelector("span");
+  span.remove();
+  assert_equals(html_direction(slot), "ltr", "slot is reset to ltr");
+  tree.remove();
+}, 'Removing child of slotted content changes direction on dir=auto slot');
+
+test(() => {
+  let tree;
+  tree = setup_tree(`
+    <div>
+      <span>اختبر</span>
+      <p>Text</p>
+    </div>
+  `);
+  let p = tree.querySelector("p");
+  assert_true(p.matches(":dir(ltr)"), "child initially ltr");
+  tree.dir = "auto";
+  assert_true(p.matches(":dir(rtl)"), "child updated to rtl");
+  tree.remove();
+}, 'Child directionality gets updated when dir=auto is set on parent');
+
+test(() => {
+  let [tree, shadow] = setup_tree(`
+    <div>
+      <div id=root>
+        <input value="اختبر">
+      </div>
+    </div>
+  `,`
+    <slot dir=auto></slot>
+  `);
+  let slot = shadow.querySelector("slot");
+  assert_equals(html_direction(slot), "rtl");
+  let inp = tree.querySelector("input");
+  inp.value = "abc";
+  assert_equals(html_direction(slot), "ltr");
+  tree.remove();
+}, 'dir=auto slot is updated by text in value of input element children');
+
+test(() => {
+  let [tree, shadow] = setup_tree(`
+    <div>
+      <div id=root>
+        <input value="اختبر">
+        abc
+      </div>
+    </div>
+  `,`
+    <slot dir=auto></slot>
+  `);
+  let slot = shadow.querySelector("slot");
+  assert_equals(html_direction(slot), "rtl");
+  let inp = tree.querySelector("input");
+  inp.type = "month";
+  assert_equals(html_direction(slot), "ltr");
+  tree.remove();
+}, 'dir=auto slot is updated if input stops being auto-directionality form-associated');
+
+test(() => {
+  let [tree, shadow] = setup_tree(`
+    <div>
+      <div id=root dir=ltr>
+        <span>اختبر</span>
+      </div>
+    </div>
+  `,`
+    <div dir=auto id=container>
+      <slot></slot>
+    </div>
+  `);
+  let div = shadow.querySelector("#container");
+  let host = tree.querySelector("#root");
+  assert_equals(html_direction(div), 'ltr', 'ltr inherited from host despite rtl content');
+  // set rtl on host directly, test it is propagated through slots
+  host.dir = "rtl";
+  assert_equals(html_direction(div), 'rtl', 'host dir change propagated via slot');
+  host.dir = "";
+  assert_equals(html_direction(host), 'ltr', 'host dir reset to ltr');
+  assert_equals(html_direction(div), 'ltr', 'host dir change propagated via slot');
+  // host inherits rtl from parent, test it is still propagated through slots
+  tree.dir = "rtl";
+  assert_equals(html_direction(host), 'rtl', 'host inherited rtl from parent');
+  assert_equals(html_direction(div), 'rtl', 'host dir change propagated via slot');
+  tree.remove();
+}, 'slot provides updated directionality from host to a dir=auto container');
diff --git a/tests/wpt/tests/html/dom/elements/global-attributes/dir-shadow-utils.js b/tests/wpt/tests/html/dom/elements/global-attributes/dir-shadow-utils.js
index c7d89cf9082..26fa30efe8f 100644
--- a/tests/wpt/tests/html/dom/elements/global-attributes/dir-shadow-utils.js
+++ b/tests/wpt/tests/html/dom/elements/global-attributes/dir-shadow-utils.js
@@ -6,3 +6,19 @@ function html_direction(element) {
   }
   return is_ltr ? "ltr" : "rtl";
 }
+
+function setup_tree(light_tree, shadow_tree) {
+  let body = document.body;
+  let old_length = body.childNodes.length;
+  body.insertAdjacentHTML("beforeend", light_tree.trim());
+  if (body.childNodes.length != old_length + 1) {
+    throw "unexpected markup";
+  }
+  let result = body.lastChild;
+  if (shadow_tree) {
+    let shadow = result.querySelector("#root").attachShadow({mode: "open"});
+    shadow.innerHTML = shadow_tree.trim();
+    return [result, shadow];
+  }
+  return result;
+}
diff --git a/tests/wpt/tests/html/dom/elements/global-attributes/dir-slots-directionality.html b/tests/wpt/tests/html/dom/elements/global-attributes/dir-slots-directionality.html
index db783fc55ca..c0a11ba9a90 100644
--- a/tests/wpt/tests/html/dom/elements/global-attributes/dir-slots-directionality.html
+++ b/tests/wpt/tests/html/dom/elements/global-attributes/dir-slots-directionality.html
@@ -7,91 +7,222 @@
 <link rel="help" href="https://github.com/whatwg/html/issues/3699">
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
-<div id="host1"><span></span></div>
-<div id="host2" dir="rtl"></div>
-<span id="host3" dir="auto"></span>
-<div id="host4">اختبر</div>
-<div id="host5"></div>
-<div id="host6">اختبر</div>
+<script src="dir-shadow-utils.js"></script>
+
+<div></div>
+
 <script>
 
 test(() => {
-  let root1 = host1.attachShadow({mode:"open"});
-  root1.innerHTML = '<slot dir="rtl"></slot>';
-  let span = host1.firstChild;
+  let [tree, shadow] = setup_tree(`
+    <div>
+      <div id="root">
+        <span></span>
+      </div>
+    </div>
+  `,`
+    <slot dir="rtl"></slot>
+  `);
+  let span = tree.querySelector("span");
   assert_equals(getComputedStyle(span).direction, "rtl");
-  assert_true(span.matches(":dir(ltr)"));
+  assert_equals(html_direction(span), "ltr");
+  tree.remove();
 }, 'Slots: Directionality: dir=rtl on slot');
 
 test(() => {
-  let root2 = host2.attachShadow({mode:"open"});
-  root2.innerHTML = '<span></span>';
-  let span = root2.querySelector("span");
+  let [tree, shadow] = setup_tree(`
+    <div>
+      <div id="root" dir="rtl"></div>
+    </div>
+  `,`
+    <span></span>
+  `);
+  let span = shadow.querySelector("span");
   assert_equals(getComputedStyle(span).direction, "rtl");
-  assert_true(span.matches(":dir(rtl)"));
+  assert_equals(html_direction(span), "rtl");
+  tree.remove();
 }, 'Slots: Directionality: dir=rtl on host');
 
 test(() => {
-  let root3 = host3.attachShadow({mode:"open"});
-  root3.innerHTML = `اختبر`;
-  let span = host3;
+  let [tree, shadow] = setup_tree(`
+    <div>
+      <span id="root" dir="auto"></span>
+    </div>
+  `,`
+    اختبر
+  `);
+  let span = tree.querySelector("span");
   assert_equals(getComputedStyle(span).direction, "ltr");
-  assert_true(span.matches(":dir(ltr)"));
+  assert_equals(html_direction(span), "ltr");
+  tree.remove();
 }, 'Slots: Directionality: dir=auto on host with Arabic shadow tree content');
 
 test(() => {
-  let root4 = host4.attachShadow({mode:"open"});
-  root4.innerHTML = '<span dir="auto"><slot></slot></span>';
-  let span = root4.querySelector("span");
+  let [tree, shadow] = setup_tree(`
+    <div>
+      <div id="root">
+        اختبر
+      </div>
+    </div>
+  `,`
+    <span dir="auto">
+      <slot></slot>
+    </span>
+  `);
+  let span = shadow.querySelector("span");
   assert_equals(getComputedStyle(span).direction, "ltr");
-  assert_true(span.matches(":dir(ltr)"));
+  assert_equals(html_direction(span), "ltr");
+  tree.remove();
 }, 'Slots: Directionality: dir=auto in shadow tree with Arabic light tree content');
 
 test(() => {
-  let root5 = host5.attachShadow({mode:"open"});
-  root5.innerHTML = '<span dir="auto"><slot>اختبر</slot></span>';
-  let span = root5.querySelector("span");
+  let [tree, shadow] = setup_tree(`
+    <div>
+      <div id="root"></div>
+    </div>
+  `,`
+    <span dir="auto">
+      <slot>
+        اختبر
+      </slot>
+    </span>
+  `);
+  let span = shadow.querySelector("span");
   assert_equals(getComputedStyle(span).direction, "ltr");
-  assert_true(span.matches(":dir(ltr)"));
+  assert_equals(html_direction(span), "ltr");
+  tree.remove();
 }, 'Slots: Directionality: dir=auto in shadow tree with Arabic shadow tree content');
 
 test(() => {
-  let root6 = host6.attachShadow({mode:"open"});
-  root6.innerHTML = '<slot dir="auto"></slot>';
-  let span = root6.querySelector("slot");
-  assert_equals(getComputedStyle(span).direction, "rtl");
-  assert_true(span.matches(":dir(rtl)"));
+  let [tree, shadow] = setup_tree(`
+    <div>
+      <div id="root">
+        اختبر
+      </div>
+    </div>
+  `,`
+    <slot dir="auto"></slot>
+  `);
+  let slot = shadow.querySelector("slot");
+  assert_equals(getComputedStyle(slot).direction, "rtl");
+  assert_equals(html_direction(slot), "rtl");
+  tree.remove();
 }, 'Slots: Directionality: dir=auto on slot with Arabic light tree content');
 
 test(() => {
-  let host = document.createElement("div");
-  host.dir = "rtl";
-  document.body.appendChild(host);
-  let root = host.attachShadow({mode:"open"});
-  root.innerHTML = '<section dir="ltr"><div dir="auto"><slot></slot>A</div></section>';
-  let div = root.querySelector("div");
-  assert_true(div.matches(":dir(rtl)"));
-  host.remove();
+  let [tree, shadow] = setup_tree(`
+    <div>
+      <div id="root" dir="rtl"></div>
+    </div>
+  `,`
+    <section dir="ltr">
+      <div dir="auto">
+        <slot></slot>
+        A
+      </div>
+    </section>
+  `);
+  let div = shadow.querySelector("div");
+  assert_equals(html_direction(div), "rtl");
+  tree.remove();
 }, 'slot provides its directionality (from host) to a dir=auto container');
 
 test(() => {
-  let host = document.createElement("div");
-  document.body.appendChild(host);
-  let root = host.attachShadow({mode:"open"});
-  root.innerHTML = '<div dir="auto"><span dir="ltr">A</span>\u05D0</div><slot></slot>';
-  let div = root.querySelector("div");
-  assert_true(div.matches(":dir(rtl)"));
-  host.remove();
+  let [tree, shadow] = setup_tree(`
+    <div>
+      <div id="root"></div>
+    </div>
+  `,`
+    <div dir="auto">
+      <span dir="ltr">
+        A
+      </span>
+      \u05D0
+    </div>
+    <slot></slot>
+  `);
+  let div = shadow.querySelector("div");
+  assert_equals(html_direction(div), "rtl");
+  tree.remove();
 }, 'children with dir attribute are skipped by dir=auto');
 
 test(() => {
-  let host = document.createElement("div");
-  document.body.appendChild(host);
-  let root = host.attachShadow({mode:"open"});
-  root.innerHTML = '<div dir="auto"><slot dir="ltr"></slot>\u05D0</div>';
-  let div = root.querySelector("div");
-  assert_true(div.matches(":dir(rtl)"));
-  host.remove();
+  let [tree, shadow] = setup_tree(`
+    <div>
+      <div id="root"></div>
+    </div>
+  `,`
+    <div dir="auto"><slot dir="ltr"></slot>\u05D0</div>
+  `);
+  let div = shadow.querySelector("div");
+  assert_equals(html_direction(div), "rtl");
+  tree.remove();
 }, 'slot with dir attribute is skipped by dir=auto');
 
+test(() => {
+  let [tree, shadow] = setup_tree(`
+    <div>
+      <div id="root" dir="auto">
+        <div dir="ltr">اختبر</div>
+        <span>Text</span>
+      </div>
+    </div>
+  `,`
+    <slot dir="auto"></slot>
+  `);
+  let div = tree.querySelector("#root");
+  assert_equals(html_direction(div), "ltr");
+  let slot = shadow.querySelector("slot");
+  assert_equals(html_direction(slot), "rtl");
+  tree.remove();
+}, 'dir=auto slot ignores dir attribute of assigned nodes');
+
+test(() => {
+  let [tree, shadow] = setup_tree(`
+    <div>
+      <div id="root">
+        <bdi class="name">اختبر</bdi>
+      </div>
+    </div>
+  `, `
+    <slot dir="auto"></slot>
+  `);
+  let slot = shadow.querySelector("slot");
+  assert_equals(html_direction(slot), "rtl");
+  tree.remove();
+}, 'dir=auto slot considers text in bdi assigned nodes');
+
+test(() => {
+  let [tree, shadow] = setup_tree(`
+    <div>
+      <div id=root>
+        <input value="اختبر">
+      </div>
+    </div>
+  `,`
+    <slot dir=auto></slot>
+  `);
+  let inp = tree.querySelector("input");
+  assert_equals(html_direction(inp), "ltr");
+  let slot = shadow.querySelector("slot");
+  assert_equals(html_direction(slot), "rtl");
+  tree.remove();
+
+  [tree, shadow] = setup_tree(`
+    <div>
+      <div id=root>
+        <input value=" ">
+        اختبر
+      </div>
+    </div>
+  `,`
+    <slot dir=auto></slot>
+  `);
+  inp = tree.querySelector("input");
+  assert_equals(html_direction(inp), "ltr");
+  slot = shadow.querySelector("slot");
+  assert_equals(html_direction(slot), "ltr", "no strong character in value counts as ltr");
+  tree.remove();
+}, 'dir=auto slot considers text in value of input element children');
+
 </script>
diff --git a/tests/wpt/tests/html/rendering/widgets/input-checkbox-appearance-none-dynamic-crash.html b/tests/wpt/tests/html/rendering/widgets/input-checkbox-appearance-none-dynamic-crash.html
new file mode 100644
index 00000000000..fb10f6a7fa6
--- /dev/null
+++ b/tests/wpt/tests/html/rendering/widgets/input-checkbox-appearance-none-dynamic-crash.html
@@ -0,0 +1,16 @@
+<style>
+input:checked {
+  appearance: none;
+}
+input:required {
+  border-bottom-style: groove;
+}
+</style>
+<script>
+document.addEventListener("DOMContentLoaded", () => {
+  a.getBoundingClientRect();
+  a.defaultChecked = true;
+  a.getBoundingClientRect();
+})
+</script>
+<input id="a" required="required" type="radio">
diff --git a/tests/wpt/tests/html/semantics/forms/constraints/form-validation-reportValidity.html b/tests/wpt/tests/html/semantics/forms/constraints/form-validation-reportValidity.html
index c68e21c9d5f..5f0393f9275 100644
--- a/tests/wpt/tests/html/semantics/forms/constraints/form-validation-reportValidity.html
+++ b/tests/wpt/tests/html/semantics/forms/constraints/form-validation-reportValidity.html
@@ -1,5 +1,6 @@
 <!DOCTYPE html>
 <meta charset="utf-8">
+<meta name="timeout" content="long">
 <title>The constraint validation API Test: element.reportValidity()</title>
 <link rel="author" title="Intel" href="http://www.intel.com/">
 <link rel="help" href="https://html.spec.whatwg.org/multipage/#dom-cva-reportvalidity">
diff --git a/tests/wpt/tests/html/semantics/grouping-content/the-li-element/grouping-li-reftest-list-owner-menu-ref.html b/tests/wpt/tests/html/semantics/grouping-content/the-li-element/grouping-li-reftest-list-owner-menu-ref.html
index 2b1ea76656f..fce5538f5e0 100644
--- a/tests/wpt/tests/html/semantics/grouping-content/the-li-element/grouping-li-reftest-list-owner-menu-ref.html
+++ b/tests/wpt/tests/html/semantics/grouping-content/the-li-element/grouping-li-reftest-list-owner-menu-ref.html
@@ -2,9 +2,16 @@
 <meta charset="utf-8">
 <title>list owner is calculated to be narest ancestor menu if it exists</title>
 <link rel="author" title="Domenic Denicola" href="mailto:d@domenic.me">
+<link rel="author" title="Peng Zhou" href="mailto:zhoupeng.1996@bytedance.com">
 <link rel="help" href="https://html.spec.whatwg.org/multipage/semantics.html#ordinal-value">
 <link rel="help" href="https://html.spec.whatwg.org/multipage/semantics.html#list-owner">
 
+<style>
+  li {
+    list-style-type: decimal;
+  }
+</style>
+
 <p>This test matches if the list displays similar to the following</p>
 
 <pre>1. A
@@ -22,25 +29,25 @@
 
 <hr>
 
-<ol>
+<menu>
   <li value="1">A</li>
   <li value="2">B</li>
   <li value="3">C</li>
   <li value="4">D</li>
   <li value="5">E</li>
-  <ol>
+  <menu>
     <li value="1">F</li>
     <li value="2">G</li>
-  </ol>
+  </menu>
   <li value="6">H</li>
-  <ol>
+  <menu>
     <li value="1">I</li>
     <li value="2">
       J
-      <ol>
+      <menu>
         <li value="1">K</li>
         <li value="2">L</li>
-      </ol>
+      </menu>
     </li>
-  </ol>
-</ol>
+  </menu>
+</menu>
diff --git a/tests/wpt/tests/html/semantics/interactive-elements/the-details-element/name-attribute.html b/tests/wpt/tests/html/semantics/interactive-elements/the-details-element/name-attribute.html
index 2685546e9b0..19d62de66f4 100644
--- a/tests/wpt/tests/html/semantics/interactive-elements/the-details-element/name-attribute.html
+++ b/tests/wpt/tests/html/semantics/interactive-elements/the-details-element/name-attribute.html
@@ -194,10 +194,6 @@ promise_test(async t => {
   let received_ids = [];
   let listener = event => {
     received_ids.push(event.target.id);
-    let i = 0;
-    for (let element of elements) {
-      element.setAttribute("name", `b${i++}`);
-    }
   };
   for (let element of elements) {
     element.addEventListener("DOMSubtreeModified", listener);
diff --git a/tests/wpt/tests/html/semantics/invokers/idlharness.tentative.html b/tests/wpt/tests/html/semantics/invokers/idlharness.tentative.html
index 8a86a5aaa18..e52ab063f84 100644
--- a/tests/wpt/tests/html/semantics/invokers/idlharness.tentative.html
+++ b/tests/wpt/tests/html/semantics/invokers/idlharness.tentative.html
@@ -10,7 +10,7 @@
 <script>
   idl_test(["invokers.tentative"], ["html", "dom"], (idl_array) => {
     idl_array.add_objects({
-      InvokeEvent: ['new InvokeEvent("invoke")'],
+      CommandEvent: ['new CommandEvent("invoke")'],
     });
   });
 </script>
diff --git a/tests/wpt/tests/html/semantics/invokers/invokeelement-interface.tentative.html b/tests/wpt/tests/html/semantics/invokers/invokeelement-interface.tentative.html
index 5adacadabb4..6821adf71fe 100644
--- a/tests/wpt/tests/html/semantics/invokers/invokeelement-interface.tentative.html
+++ b/tests/wpt/tests/html/semantics/invokers/invokeelement-interface.tentative.html
@@ -5,89 +5,84 @@
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
 
-<button id="invoker" invoketarget="invokee"></button>
+<button id="invoker" commandfor="invokee" command="test"></button>
 <div id="invokee"></div>
 
 <script>
   test(function () {
-    assert_equals(invoker.invokeTargetElement, invokee);
-  }, "invokeTargetElement reflects invokee HTML element");
+    assert_equals(invoker.commandForElement, invokee);
+  }, "commandForElement reflects invokee HTML element");
 
   test(function () {
     const div = document.body.appendChild(document.createElement("div"));
-    invoker.invokeTargetElement = div;
-    assert_equals(invoker.invokeTargetElement, div);
-    assert_equals(invoker.getAttribute("invoketarget"), "");
-    assert_false(invoker.hasAttribute("invokeaction"));
-  }, "invokeTargetElement reflects set value");
+    invoker.commandForElement = div;
+    assert_equals(invoker.commandForElement, div);
+    assert_equals(invoker.getAttribute("commandfor"), "");
+    assert_equals(invoker.getAttribute("command"), "test");
+  }, "commandForElement reflects set value");
 
   test(function () {
     const host = document.body.appendChild(document.createElement("div"));
     const shadow = host.attachShadow({ mode: "open" });
     const button = shadow.appendChild(document.createElement("button"));
-    button.invokeTargetElement = invokee;
-    assert_equals(button.invokeTargetElement, invokee);
-    assert_equals(invoker.getAttribute("invoketarget"), "");
-    assert_false(invoker.hasAttribute("invokeaction"));
-  }, "invokeTargetElement reflects set value across shadow root into light dom");
+    button.commandForElement = invokee;
+    assert_equals(button.commandForElement, invokee);
+    assert_equals(invoker.getAttribute("commandfor"), "");
+    assert_equals(invoker.getAttribute("command"), "test");
+  }, "commandForElement reflects set value across shadow root into light dom");
 
   test(function () {
     const host = document.body.appendChild(document.createElement("div"));
     const shadow = host.attachShadow({ mode: "open" });
     const div = shadow.appendChild(document.createElement("div"));
-    invoker.invokeTargetElement = div;
-    assert_equals(invoker.invokeTargetElement, null);
-    assert_equals(invoker.getAttribute("invoketarget"), "");
-    assert_false(invoker.hasAttribute("invokeaction"));
-  }, "invokeTargetElement does not reflect set value inside shadowroot");
+    invoker.commandForElement = div;
+    assert_equals(invoker.commandForElement, null);
+    assert_equals(invoker.getAttribute("commandfor"), "");
+    assert_equals(invoker.getAttribute("command"), "test");
+  }, "commandForElement does not reflect set value inside shadowroot");
 
   test(function () {
     assert_throws_js(
       TypeError,
       function () {
-        invoker.invokeTargetElement = {};
+        invoker.commandForElement = {};
       },
-      "invokeTargetElement attribute must be an instance of Element",
+      "commandForElement attribute must be an instance of Element",
     );
-  }, "invokeTargetElement throws error on assignment of non Element");
+  }, "commandForElement throws error on assignment of non Element");
 
   test(function () {
-    assert_false(invoker.hasAttribute("invokeaction"));
-    assert_equals(invoker.invokeAction, "");
-  }, "invokeAction reflects '' when attribute not present");
+    invoker.setAttribute("command", "");
+    assert_equals(invoker.getAttribute("command"), "");
+    assert_equals(invoker.command, "");
+  }, "command reflects '' when attribute empty, setAttribute version");
 
   test(function () {
-    invoker.setAttribute("invokeaction", "");
-    assert_equals(invoker.getAttribute("invokeaction"), "");
-    assert_equals(invoker.invokeAction, "");
-  }, "invokeAction reflects '' when attribute empty, setAttribute version");
+    invoker.command = "fooBarBaz";
+    assert_equals(invoker.getAttribute("command"), "fooBarBaz");
+    assert_equals(invoker.command, "fooBarBaz");
+  }, "command reflects same casing");
 
   test(function () {
-    invoker.invokeAction = "fooBarBaz";
-    assert_equals(invoker.getAttribute("invokeaction"), "fooBarBaz");
-    assert_equals(invoker.invokeAction, "fooBarBaz");
-  }, "invokeAction reflects same casing");
+    invoker.command = "";
+    assert_equals(invoker.getAttribute("command"), "");
+    assert_equals(invoker.command, "");
+  }, "command reflects '' when attribute empty, IDL version");
 
   test(function () {
-    invoker.invokeAction = "";
-    assert_equals(invoker.getAttribute("invokeaction"), "");
-    assert_equals(invoker.invokeAction, "");
-  }, "invokeAction reflects '' when attribute empty, IDL version");
+    invoker.command = [1, 2, 3];
+    assert_equals(invoker.getAttribute("command"), "1,2,3");
+    assert_equals(invoker.command, "1,2,3");
+  }, "command reflects tostring value");
 
   test(function () {
-    invoker.invokeAction = [1, 2, 3];
-    assert_equals(invoker.getAttribute("invokeaction"), "1,2,3");
-    assert_equals(invoker.invokeAction, "1,2,3");
-  }, "invokeAction reflects tostring value");
+    invoker.command = [];
+    assert_equals(invoker.getAttribute("command"), "");
+    assert_equals(invoker.command, "");
+  }, "command reflects '' when attribute set to []");
 
   test(function () {
-    invoker.invokeAction = [];
-    assert_equals(invoker.getAttribute("invokeaction"), "");
-    assert_equals(invoker.invokeAction, "");
-  }, "invokeAction reflects '' when attribute set to []");
-
-  test(function () {
-    invoker.invokeAction = {};
-    assert_equals(invoker.invokeAction, "[object Object]");
-  }, "invokeAction reflects tostring value 2");
+    invoker.command = {};
+    assert_equals(invoker.command, "[object Object]");
+  }, "command reflects tostring value 2");
 </script>
diff --git a/tests/wpt/tests/html/semantics/invokers/invokeevent-dispatch-shadow.tentative.html b/tests/wpt/tests/html/semantics/invokers/invokeevent-dispatch-shadow.tentative.html
index 1ecff887608..fb2a113994f 100644
--- a/tests/wpt/tests/html/semantics/invokers/invokeevent-dispatch-shadow.tentative.html
+++ b/tests/wpt/tests/html/semantics/invokers/invokeevent-dispatch-shadow.tentative.html
@@ -25,7 +25,7 @@
     let hostEventTarget = null;
     let hostEventInvoker = null;
     slot.addEventListener(
-      "invoke",
+      "command",
       (e) => {
         childEvent = e;
         childEventTarget = e.target;
@@ -34,7 +34,7 @@
       { once: true },
     );
     host.addEventListener(
-      "invoke",
+      "command",
       (e) => {
         hostEvent = e;
         hostEventTarget = e.target;
@@ -42,13 +42,13 @@
       },
       { once: true },
     );
-    const event = new InvokeEvent("invoke", {
+    const event = new CommandEvent("command", {
       bubbles: true,
       invoker: slot,
       composed: true,
     });
     slot.dispatchEvent(event);
-    assert_true(childEvent instanceof InvokeEvent, "slot saw invoke event");
+    assert_true(childEvent instanceof CommandEvent, "slot saw invoke event");
     assert_equals(
       childEventTarget,
       slot,
@@ -74,7 +74,7 @@
       host,
       "invoker is retargeted to shadowroot host",
     );
-  }, "InvokeEvent propagates across shadow boundaries retargeting invoker");
+  }, "CommandEvent propagates across shadow boundaries retargeting invoker");
 
   test(function (t) {
     const host = document.createElement("div");
@@ -83,12 +83,13 @@
     const shadow = host.attachShadow({ mode: "open" });
     const button = shadow.appendChild(document.createElement("button"));
     const invokee = host.appendChild(document.createElement("div"));
-    button.invokeTargetElement = invokee;
+    button.commandForElement = invokee;
+    button.command = 'test-command';
     let event = null;
     let eventTarget = null;
     let eventInvoker = null;
     invokee.addEventListener(
-      "invoke",
+      "command",
       (e) => {
         event = e;
         eventTarget = e.target;
@@ -97,8 +98,8 @@
       { once: true },
     );
     button.click();
-    assert_true(event instanceof InvokeEvent);
+    assert_true(event instanceof CommandEvent);
     assert_equals(eventTarget, invokee, "target is invokee");
     assert_equals(eventInvoker, host, "invoker is host");
-  }, "cross shadow InvokeEvent retargets invoker to host element");
+  }, "cross shadow CommandEvent retargets invoker to host element");
 </script>
diff --git a/tests/wpt/tests/html/semantics/invokers/invokeevent-interface.tentative.html b/tests/wpt/tests/html/semantics/invokers/invokeevent-interface.tentative.html
index 0cfb4d5ee5f..500c05f88a1 100644
--- a/tests/wpt/tests/html/semantics/invokers/invokeevent-interface.tentative.html
+++ b/tests/wpt/tests/html/semantics/invokers/invokeevent-interface.tentative.html
@@ -14,112 +14,112 @@
 
 <script>
   test(function () {
-    const event = new InvokeEvent("test");
-    assert_equals(event.action, "");
-    assert_readonly(event, "action", "readonly attribute value");
-  }, "action is a readonly defaulting to ''");
+    const event = new CommandEvent("test");
+    assert_equals(event.command, "");
+    assert_readonly(event, "command", "readonly attribute value");
+  }, "command is a readonly defaulting to ''");
 
   test(function () {
-    const event = new InvokeEvent("test");
+    const event = new CommandEvent("test");
     assert_equals(event.invoker, null);
     assert_readonly(event, "invoker", "readonly attribute value");
   }, "invoker is readonly defaulting to null");
 
   test(function () {
-    const event = new InvokeEvent("test", { action: "sAmPle" });
-    assert_equals(event.action, "sAmPle");
-  }, "action reflects initialized attribute");
+    const event = new CommandEvent("test", { command: "sAmPle" });
+    assert_equals(event.command, "sAmPle");
+  }, "command reflects initialized attribute");
 
   test(function () {
-    const event = new InvokeEvent("test", { action: undefined });
-    assert_equals(event.action, "");
-  }, "action set to undefined");
+    const event = new CommandEvent("test", { command: undefined });
+    assert_equals(event.command, "");
+  }, "command set to undefined");
 
   test(function () {
-    const event = new InvokeEvent("test", { action: null });
-    assert_equals(event.action, "null");
-  }, "action set to null");
+    const event = new CommandEvent("test", { command: null });
+    assert_equals(event.command, "null");
+  }, "command set to null");
 
   test(function () {
-    const event = new InvokeEvent("test", { action: false });
-    assert_equals(event.action, "false");
-  }, "action set to false");
+    const event = new CommandEvent("test", { command: false });
+    assert_equals(event.command, "false");
+  }, "command set to false");
 
   test(function () {
-    const event = new InvokeEvent("test", { action: "" });
-    assert_equals(event.action, "");
-  }, "action explicitly set to empty string");
+    const event = new CommandEvent("test", { command: "" });
+    assert_equals(event.command, "");
+  }, "command explicitly set to empty string");
 
   test(function () {
-    const event = new InvokeEvent("test", { action: true });
-    assert_equals(event.action, "true");
-  }, "action set to true");
+    const event = new CommandEvent("test", { command: true });
+    assert_equals(event.command, "true");
+  }, "command set to true");
 
   test(function () {
-    const event = new InvokeEvent("test", { action: 0.5 });
-    assert_equals(event.action, "0.5");
-  }, "action set to a number");
+    const event = new CommandEvent("test", { command: 0.5 });
+    assert_equals(event.command, "0.5");
+  }, "command set to a number");
 
   test(function () {
-    const event = new InvokeEvent("test", { action: [] });
-    assert_equals(event.action, "");
-  }, "action set to []");
+    const event = new CommandEvent("test", { command: [] });
+    assert_equals(event.command, "");
+  }, "command set to []");
 
   test(function () {
-    const event = new InvokeEvent("test", { action: [1, 2, 3] });
-    assert_equals(event.action, "1,2,3");
-  }, "action set to [1, 2, 3]");
+    const event = new CommandEvent("test", { command: [1, 2, 3] });
+    assert_equals(event.command, "1,2,3");
+  }, "command set to [1, 2, 3]");
 
   test(function () {
-    const event = new InvokeEvent("test", { action: { sample: 0.5 } });
-    assert_equals(event.action, "[object Object]");
-  }, "action set to an object");
+    const event = new CommandEvent("test", { command: { sample: 0.5 } });
+    assert_equals(event.command, "[object Object]");
+  }, "command set to an object");
 
   test(function () {
-    const event = new InvokeEvent("test", {
-      action: {
+    const event = new CommandEvent("test", {
+      command: {
         toString() {
           return "sample";
         },
       },
     });
-    assert_equals(event.action, "sample");
-  }, "action set to an object with a toString function");
+    assert_equals(event.command, "sample");
+  }, "command set to an object with a toString function");
 
   test(function () {
-    const eventInit = { action: "sample", invoker: document.body };
-    const event = new InvokeEvent("test", eventInit);
-    assert_equals(event.action, "sample");
+    const eventInit = { command: "sample", invoker: document.body };
+    const event = new CommandEvent("test", eventInit);
+    assert_equals(event.command, "sample");
     assert_equals(event.invoker, document.body);
-  }, "InvokeEventInit properties set value");
+  }, "CommandEventInit properties set value");
 
   test(function () {
     const eventInit = {
-      action: "open",
+      command: "open",
       invoker: document.getElementById("div"),
     };
-    const event = new InvokeEvent("beforetoggle", eventInit);
-    assert_equals(event.action, "open");
+    const event = new CommandEvent("beforetoggle", eventInit);
+    assert_equals(event.command, "open");
     assert_equals(event.invoker, document.getElementById("div"));
-  }, "InvokeEventInit properties set value 2");
+  }, "CommandEventInit properties set value 2");
 
   test(function () {
     const eventInit = {
-      action: "closed",
+      command: "closed",
       invoker: document.getElementById("button"),
     };
-    const event = new InvokeEvent("toggle", eventInit);
-    assert_equals(event.action, "closed");
+    const event = new CommandEvent("toggle", eventInit);
+    assert_equals(event.command, "closed");
     assert_equals(event.invoker, document.getElementById("button"));
-  }, "InvokeEventInit properties set value 3");
+  }, "CommandEventInit properties set value 3");
 
   test(function () {
-    const event = new InvokeEvent("test", { invoker: undefined });
+    const event = new CommandEvent("test", { invoker: undefined });
     assert_equals(event.invoker, null);
   }, "invoker set to undefined");
 
   test(function () {
-    const event = new InvokeEvent("test", { invoker: null });
+    const event = new CommandEvent("test", { invoker: null });
     assert_equals(event.invoker, null);
   }, "invoker set to null");
 
@@ -127,7 +127,7 @@
     assert_throws_js(
       TypeError,
       function () {
-        new InvokeEvent("test", { invoker: false });
+        new CommandEvent("test", { invoker: false });
       },
       "invoker is not an object",
     );
@@ -137,7 +137,7 @@
     assert_throws_js(
       TypeError,
       function () {
-        const event = new InvokeEvent("test", { invoker: true });
+        const event = new CommandEvent("test", { invoker: true });
       },
       "invoker is not an object",
     );
@@ -147,7 +147,7 @@
     assert_throws_js(
       TypeError,
       function () {
-        const event = new InvokeEvent("test", { invoker: {} });
+        const event = new CommandEvent("test", { invoker: {} });
       },
       "invoker is not an object",
     );
@@ -157,8 +157,8 @@
     assert_throws_js(
       TypeError,
       function () {
-        const eventInit = { action: "closed", invoker: new XMLHttpRequest() };
-        const event = new InvokeEvent("toggle", eventInit);
+        const eventInit = { command: "closed", invoker: new XMLHttpRequest() };
+        const event = new CommandEvent("toggle", eventInit);
       },
       "invoker is not an Element",
     );
diff --git a/tests/wpt/tests/html/semantics/invokers/invoketarget-button-event-dispatch.tentative.html b/tests/wpt/tests/html/semantics/invokers/invoketarget-button-event-dispatch.tentative.html
index 9120cc31926..c5dfe14f90b 100644
--- a/tests/wpt/tests/html/semantics/invokers/invoketarget-button-event-dispatch.tentative.html
+++ b/tests/wpt/tests/html/semantics/invokers/invoketarget-button-event-dispatch.tentative.html
@@ -11,79 +11,90 @@
 <script src="resources/invoker-utils.js"></script>
 
 <div id="invokee"></div>
-<button id="invokerbutton" invoketarget="invokee"></button>
+<button id="invokerbutton" commandfor="invokee" command="custom-command"></button>
+<form id="aform"></form>
 
 <script>
+  aform.addEventListener('submit', (e) => (e.preventDefault()));
+
+  function resetState() {
+    invokerbutton.setAttribute("commandfor", "invokee");
+    invokerbutton.setAttribute("command", "custom-command");
+    invokerbutton.removeAttribute("disabled");
+    invokerbutton.removeAttribute("form");
+    invokerbutton.removeAttribute("type");
+  }
+
   promise_test(async function (t) {
     let event = null;
-    invokee.addEventListener("invoke", (e) => (event = e), { once: true });
+    invokee.addEventListener("command", (e) => (event = e), { once: true });
     await clickOn(invokerbutton);
-    assert_true(event instanceof InvokeEvent, "event is InvokeEvent");
-    assert_equals(event.type, "invoke", "type");
+    assert_true(event instanceof CommandEvent, "event is CommandEvent");
+    assert_equals(event.type, "command", "type");
     assert_equals(event.bubbles, false, "bubbles");
     assert_equals(event.composed, true, "composed");
     assert_equals(event.isTrusted, true, "isTrusted");
-    assert_equals(event.action, "", "action");
+    assert_equals(event.command, "custom-command", "command");
     assert_equals(event.target, invokee, "target");
     assert_equals(event.invoker, invokerbutton, "invoker");
   }, "event dispatches on click");
 
   // valid custom invokeactions
   ["-foo", "foo-", "cAsE-cArRiEs", "-", "-a-", "a-b", "---", "show-picker"].forEach(
-    (action) => {
+    (command) => {
       promise_test(async function (t) {
-        t.add_cleanup(() => invokerbutton.removeAttribute("invokeaction"));
+        t.add_cleanup(resetState);
         let event = null;
-        invokee.addEventListener("invoke", (e) => (event = e), { once: true });
-        invokerbutton.invokeAction = action;
+        invokee.addEventListener("command", (e) => (event = e), { once: true });
+        invokerbutton.command = command;
         await clickOn(invokerbutton);
-        assert_true(event instanceof InvokeEvent, "event is InvokeEvent");
-        assert_equals(event.type, "invoke", "type");
+        assert_true(event instanceof CommandEvent, "event is CommandEvent");
+        assert_equals(event.type, "command", "type");
         assert_equals(event.bubbles, false, "bubbles");
         assert_equals(event.composed, true, "composed");
         assert_equals(event.isTrusted, true, "isTrusted");
-        assert_equals(event.action, action, "action");
+        assert_equals(event.command, command, "command");
         assert_equals(event.target, invokee, "target");
         assert_equals(event.invoker, invokerbutton, "invoker");
-      }, `setting custom invokeAction property to ${action} (must include dash) sets event action`);
+      }, `setting custom command property to ${command} (must include dash) sets event command`);
 
       promise_test(async function (t) {
-        t.add_cleanup(() => invokerbutton.removeAttribute("invokeaction"));
+        t.add_cleanup(resetState);
         let event = null;
-        invokee.addEventListener("invoke", (e) => (event = e), { once: true });
-        invokerbutton.setAttribute("invokeaction", action);
+        invokee.addEventListener("command", (e) => (event = e), { once: true });
+        invokerbutton.setAttribute("command", command);
         await clickOn(invokerbutton);
-        assert_true(event instanceof InvokeEvent, "event is InvokeEvent");
-        assert_equals(event.type, "invoke", "type");
+        assert_true(event instanceof CommandEvent, "event is CommandEvent");
+        assert_equals(event.type, "command", "type");
         assert_equals(event.bubbles, false, "bubbles");
         assert_equals(event.composed, true, "composed");
         assert_equals(event.isTrusted, true, "isTrusted");
-        assert_equals(event.action, action, "action");
+        assert_equals(event.command, command, "command");
         assert_equals(event.target, invokee, "target");
         assert_equals(event.invoker, invokerbutton, "invoker");
-      }, `setting custom invokeaction attribute to ${action} (must include dash) sets event action`);
+      }, `setting custom command attribute to ${command} (must include dash) sets event command`);
     },
   );
 
   // invalid custom invokeactions
-  ["foo", "foobar", "foo bar", "em—dash", "hidedocument"].forEach((action) => {
+  ["foo", "foobar", "foo bar", "em—dash", "hidedocument"].forEach((command) => {
     promise_test(async function (t) {
-      t.add_cleanup(() => invokerbutton.removeAttribute("invokeaction"));
+      t.add_cleanup(resetState);
       let event = null;
-      invokee.addEventListener("invoke", (e) => (event = e), { once: true });
-      invokerbutton.invokeAction = action;
+      invokee.addEventListener("command", (e) => (event = e), { once: true });
+      invokerbutton.command = command;
       await clickOn(invokerbutton);
       assert_equals(event, null, "event should not have fired");
-    }, `setting custom invokeAction property to ${action} (no dash) did not dispatch an event`);
+    }, `setting custom command property to ${command} (no dash) did not dispatch an event`);
 
     promise_test(async function (t) {
-      t.add_cleanup(() => invokerbutton.removeAttribute("invokeaction"));
+      t.add_cleanup(resetState);
       let event = null;
-      invokee.addEventListener("invoke", (e) => (event = e), { once: true });
-      invokerbutton.setAttribute("invokeaction", action);
+      invokee.addEventListener("command", (e) => (event = e), { once: true });
+      invokerbutton.setAttribute("command", command);
       await clickOn(invokerbutton);
       assert_equals(event, null, "event should not have fired");
-    }, `setting custom invokeaction attribute to ${action} (no dash) did not dispatch an event`);
+    }, `setting custom command attribute to ${command} (no dash) did not dispatch an event`);
   });
 
   promise_test(async function (t) {
@@ -96,7 +107,7 @@
       { once: true },
     );
     invokee.addEventListener(
-      "invoke",
+      "command",
       (event) => {
         called = true;
       },
@@ -107,52 +118,49 @@
   }, "event does not dispatch if click:preventDefault is called");
 
   promise_test(async function (t) {
-    t.add_cleanup(() => invokerbutton.removeAttribute("disabled"));
+    t.add_cleanup(resetState);
     let called = false;
-    invokee.addEventListener(
-      "invoke",
-      (event) => {
-        called = true;
-      },
-      { once: true },
-    );
+    invokee.addEventListener("command", (e) => (called = true), { once: true });
     invokerbutton.setAttribute("disabled", "");
     await clickOn(invokerbutton);
     assert_false(called, "event was not called");
   }, "event does not dispatch if invoker is disabled");
 
   promise_test(async function (t) {
-    svgInvokee = document.createElementNS("http://www.w3.org/2000/svg", "svg");
-    t.add_cleanup(() => {
-      invokerbutton.invokeTargetElement = invokee;
-      svgInvokee.remove();
-    });
-    document.body.append(svgInvokee);
+    t.add_cleanup(resetState);
     let called = false;
+    invokee.addEventListener("command", (e) => (called = true), { once: true });
+    invokerbutton.setAttribute("form", "aform");
+    await clickOn(invokerbutton);
+    assert_false(called, "event was not called");
+  }, "event does not dispatch if invoker is form associated without `type`");
+
+  promise_test(async function (t) {
+    t.add_cleanup(resetState);
+    let called = false;
+    invokee.addEventListener("command", (e) => (called = true), { once: true });
+    invokerbutton.setAttribute("form", "aform");
+    invokerbutton.setAttribute("type", "button");
+    await clickOn(invokerbutton);
+    assert_true(called, "event was not called");
+  }, "event dispatches if invoker is form associated with `type=button`");
+
+  promise_test(async function (t) {
+    svgInvokee = document.createElementNS("http://www.w3.org/2000/svg", "svg");
+    svgInvokee.setAttribute("id", "svg-invokee");
+    t.add_cleanup(resetState);
+    document.body.append(svgInvokee);
     assert_false(svgInvokee instanceof HTMLElement);
     assert_true(svgInvokee instanceof Element);
-    let eventInvoker = null;
-    svgInvokee.addEventListener(
-      "invoke",
-      (event) => {
-        eventInvoker = event.invoker;
-        eventTarget = event.target;
-        called = true;
-      },
-      { once: true },
-    );
-    invokerbutton.invokeTargetElement = svgInvokee;
+    let event = null;
+    svgInvokee.addEventListener("command", (e) => (event = e), { once: true });
+    invokerbutton.setAttribute("commandfor", "svg-invokee");
+    invokerbutton.setAttribute("command", "custom-command");
+    assert_equals(invokerbutton.commandForElement, svgInvokee);
     await clickOn(invokerbutton);
-    assert_true(called, "event was called");
-    assert_equals(
-      eventInvoker,
-      invokerbutton,
-      "event.invoker is set to right element",
-    );
-    assert_equals(
-      eventTarget,
-      svgInvokee,
-      "event.target is set to right element",
-    );
+    assert_not_equals(event, null, "event was called");
+    assert_true(event instanceof CommandEvent, "event is CommandEvent");
+    assert_equals(event.invoker, invokerbutton, "event.invoker is set to right element");
+    assert_equals(event.target, svgInvokee, "event.target is set to right element");
   }, "event dispatches if invokee is non-HTML Element");
 </script>
diff --git a/tests/wpt/tests/html/semantics/invokers/invoketarget-fullscreen-behavior.tentative.html b/tests/wpt/tests/html/semantics/invokers/invoketarget-fullscreen-behavior.tentative.html
index 2e2c5f683f0..1210b8637de 100644
--- a/tests/wpt/tests/html/semantics/invokers/invoketarget-fullscreen-behavior.tentative.html
+++ b/tests/wpt/tests/html/semantics/invokers/invoketarget-fullscreen-behavior.tentative.html
@@ -12,65 +12,47 @@
 
 <div id="invokee">
   Fullscreen content
-  <button id="invokerbutton" invoketarget="invokee"></button>
+  <button id="invokerbutton" commandfor="invokee"></button>
 </div>
 
 <script>
-  // auto
-
-  promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      if (document.fullscreenElement) await document.exitFullscreen();
-    });
-    assert_false(invokee.matches(":fullscreen"));
-    await clickOn(invokerbutton);
-    assert_false(invokee.matches(":fullscreen"));
-  }, "invoking div with auto action is no-op");
+  async function resetState() {
+    invokerbutton.setAttribute("command", "toggleFullscreen");
+    if (document.fullscreenElement) await document.exitFullscreen();
+  }
 
   // toggleFullscreen
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      if (document.fullscreenElement) await document.exitFullscreen();
-    });
+    t.add_cleanup(resetState);
     assert_false(invokee.matches(":fullscreen"));
-    invokerbutton.setAttribute("invokeaction", "toggleFullscreen");
+    invokerbutton.setAttribute("command", "toggleFullscreen");
     await clickOn(invokerbutton);
     assert_true(invokee.matches(":fullscreen"));
   }, "invoking div with toggleFullscreen action makes div fullscreen");
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      if (document.fullscreenElement) await document.exitFullscreen();
-    });
+    t.add_cleanup(resetState);
     assert_false(invokee.matches(":fullscreen"));
-    invokerbutton.setAttribute("invokeaction", "toggleFullscreen");
+    invokerbutton.setAttribute("command", "toggleFullscreen");
     invokerbutton.click();
     assert_false(invokee.matches(":fullscreen"));
   }, "invoking div with toggleFullscreen action (without user activation) is a no-op");
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      if (document.fullscreenElement) await document.exitFullscreen();
-    });
-    invokee.addEventListener("invoke", (e) => e.preventDefault(), {
+    t.add_cleanup(resetState);
+    invokee.addEventListener("command", (e) => e.preventDefault(), {
       once: true,
     });
     assert_false(invokee.matches(":fullscreen"));
-    invokerbutton.setAttribute("invokeaction", "toggleFullscreen");
+    invokerbutton.setAttribute("command", "toggleFullscreen");
     await clickOn(invokerbutton);
     assert_false(invokee.matches(":fullscreen"));
   }, "invoking div with toggleFullscreen action and preventDefault is a no-op");
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      if (document.fullscreenElement) await document.exitFullscreen();
-    });
-    invokerbutton.setAttribute("invokeaction", "toggleFullscreen");
+    t.add_cleanup(resetState);
+    invokerbutton.setAttribute("command", "toggleFullscreen");
     await test_driver.bless('go fullscreen');
     await invokee.requestFullscreen();
     assert_true(invokee.matches(":fullscreen"));
@@ -79,11 +61,8 @@
   }, "invoking fullscreen div with toggleFullscreen action exits fullscreen");
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      if (document.fullscreenElement) await document.exitFullscreen();
-    });
-    invokerbutton.setAttribute("invokeaction", "tOgGlEFullscreen");
+    t.add_cleanup(resetState);
+    invokerbutton.setAttribute("command", "tOgGlEFullscreen");
     await test_driver.bless('go fullscreen');
     await invokee.requestFullscreen();
     assert_true(invokee.matches(":fullscreen"));
@@ -94,36 +73,27 @@
   // requestFullscreen
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      if (document.fullscreenElement) await document.exitFullscreen();
-    });
+    t.add_cleanup(resetState);
     assert_false(invokee.matches(":fullscreen"));
-    invokerbutton.setAttribute("invokeaction", "requestFullscreen");
+    invokerbutton.setAttribute("command", "requestFullscreen");
     await clickOn(invokerbutton);
     assert_true(invokee.matches(":fullscreen"));
   }, "invoking div with requestFullscreen action makes div fullscreen");
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      if (document.fullscreenElement) await document.exitFullscreen();
-    });
-    invokee.addEventListener("invoke", (e) => e.preventDefault(), {
+    t.add_cleanup(resetState);
+    invokee.addEventListener("command", (e) => e.preventDefault(), {
       once: true,
     });
     assert_false(invokee.matches(":fullscreen"));
-    invokerbutton.setAttribute("invokeaction", "requestFullscreen");
+    invokerbutton.setAttribute("command", "requestFullscreen");
     await clickOn(invokerbutton);
     assert_false(invokee.matches(":fullscreen"));
   }, "invoking div with requestFullscreen action and preventDefault is a no-op");
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      if (document.fullscreenElement) await document.exitFullscreen();
-    });
-    invokerbutton.setAttribute("invokeaction", "requestFullscreen");
+    t.add_cleanup(resetState);
+    invokerbutton.setAttribute("command", "requestFullscreen");
     await test_driver.bless('go fullscreen');
     await invokee.requestFullscreen();
     assert_true(invokee.matches(":fullscreen"));
@@ -134,22 +104,16 @@
   // exitFullscreen
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      if (document.fullscreenElement) await document.exitFullscreen();
-    });
+    t.add_cleanup(resetState);
     assert_false(invokee.matches(":fullscreen"));
-    invokerbutton.setAttribute("invokeaction", "exitFullscreen");
+    invokerbutton.setAttribute("command", "exitFullscreen");
     await clickOn(invokerbutton);
     assert_false(invokee.matches(":fullscreen"));
   }, "invoking div with exitFullscreen action is a no-op");
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      if (document.fullscreenElement) await document.exitFullscreen();
-    });
-    invokerbutton.setAttribute("invokeaction", "exitFullscreen");
+    t.add_cleanup(resetState);
+    invokerbutton.setAttribute("command", "exitFullscreen");
     await test_driver.bless('go fullscreen');
     await invokee.requestFullscreen();
     assert_true(invokee.matches(":fullscreen"));
@@ -158,14 +122,11 @@
   }, "invoking fullscreen div with exitFullscreen action exits fullscreen");
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      if (document.fullscreenElement) await document.exitFullscreen();
-    });
-    invokee.addEventListener("invoke", (e) => e.preventDefault(), {
+    t.add_cleanup(resetState);
+    invokee.addEventListener("command", (e) => e.preventDefault(), {
       once: true,
     });
-    invokerbutton.setAttribute("invokeaction", "exitFullscreen");
+    invokerbutton.setAttribute("command", "exitFullscreen");
     await test_driver.bless('go fullscreen');
     await invokee.requestFullscreen();
     assert_true(invokee.matches(":fullscreen"));
diff --git a/tests/wpt/tests/html/semantics/invokers/invoketarget-on-audio-behavior.tentative.html b/tests/wpt/tests/html/semantics/invokers/invoketarget-on-audio-behavior.tentative.html
index 37acb7a5396..309a91e2842 100644
--- a/tests/wpt/tests/html/semantics/invokers/invoketarget-on-audio-behavior.tentative.html
+++ b/tests/wpt/tests/html/semantics/invokers/invoketarget-on-audio-behavior.tentative.html
@@ -11,38 +11,22 @@
 <script src="resources/invoker-utils.js"></script>
 
 <audio controls id="invokee" src="/media/sound_5.mp3"></audio>
-<button id="invokerbutton" invoketarget="invokee"></button>
+<button id="invokerbutton" commandfor="invokee" command="mute"></button>
 
 <script>
-  // auto
-
-  promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      invokee.pause();
-      invokee.currentTime = 0;
-      invokee.muted = false;
-    });
-    assert_true(invokee.paused);
-    invokerbutton.setAttribute("invokeaction", "");
-    await clickOn(invokerbutton);
-    await new Promise((resolve) => {
-      requestAnimationFrame(resolve);
-    });
-    assert_true(invokee.paused);
-  }, "invoking audio with auto action is no-op");
+  function resetState() {
+    invokerbutton.setAttribute("command", "mute");
+    invokee.pause();
+    invokee.currentTime = 0;
+    invokee.muted = false;
+  }
 
   // playpause
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      invokee.pause();
-      invokee.currentTime = 0;
-      invokee.muted = false;
-    });
+    t.add_cleanup(resetState);
     assert_true(invokee.paused);
-    invokerbutton.setAttribute("invokeaction", "playpause");
+    invokerbutton.setAttribute("command", "playpause");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -51,14 +35,9 @@
   }, "invoking audio with playpause action makes audio play");
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      invokee.pause();
-      invokee.currentTime = 0;
-      invokee.muted = false;
-    });
+    t.add_cleanup(resetState);
     assert_true(invokee.paused);
-    invokerbutton.setAttribute("invokeaction", "playpause");
+    invokerbutton.setAttribute("command", "playpause");
     invokerbutton.click();
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -67,17 +46,12 @@
   }, "invoking audio with playpause action (without user activation) is a no-op");
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      invokee.pause();
-      invokee.currentTime = 0;
-      invokee.muted = false;
-    });
-    invokee.addEventListener("invoke", (e) => e.preventDefault(), {
+    t.add_cleanup(resetState);
+    invokee.addEventListener("command", (e) => e.preventDefault(), {
       once: true,
     });
     assert_true(invokee.paused);
-    invokerbutton.setAttribute("invokeaction", "playpause");
+    invokerbutton.setAttribute("command", "playpause");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -86,16 +60,11 @@
   }, "invoking audio with playpause action and preventDefault is a no-op");
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      invokee.pause();
-      invokee.currentTime = 0;
-      invokee.muted = false;
-    });
+    t.add_cleanup(resetState);
     await test_driver.bless("play audio");
     invokee.play();
     assert_false(invokee.paused);
-    invokerbutton.setAttribute("invokeaction", "playpause");
+    invokerbutton.setAttribute("command", "playpause");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -106,14 +75,9 @@
   // play
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      invokee.pause();
-      invokee.currentTime = 0;
-      invokee.muted = false;
-    });
+    t.add_cleanup(resetState);
     assert_true(invokee.paused);
-    invokerbutton.setAttribute("invokeaction", "play");
+    invokerbutton.setAttribute("command", "play");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -122,14 +86,9 @@
   }, "invoking audio with play action makes audio play");
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      invokee.pause();
-      invokee.currentTime = 0;
-      invokee.muted = false;
-    });
+    t.add_cleanup(resetState);
     assert_true(invokee.paused);
-    invokerbutton.setAttribute("invokeaction", "play");
+    invokerbutton.setAttribute("command", "play");
     invokerbutton.click();
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -138,17 +97,12 @@
   }, "invoking audio with play action (without user activation) is a no-op");
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      invokee.pause();
-      invokee.currentTime = 0;
-      invokee.muted = false;
-    });
-    invokee.addEventListener("invoke", (e) => e.preventDefault(), {
+    t.add_cleanup(resetState);
+    invokee.addEventListener("command", (e) => e.preventDefault(), {
       once: true,
     });
     assert_true(invokee.paused);
-    invokerbutton.setAttribute("invokeaction", "play");
+    invokerbutton.setAttribute("command", "play");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -157,16 +111,11 @@
   }, "invoking audio with play action and preventDefault is a no-op");
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      invokee.pause();
-      invokee.currentTime = 0;
-      invokee.muted = false;
-    });
+    t.add_cleanup(resetState);
     await test_driver.bless("play audio");
     invokee.play();
     assert_false(invokee.paused);
-    invokerbutton.setAttribute("invokeaction", "play");
+    invokerbutton.setAttribute("command", "play");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -177,14 +126,9 @@
   // pause
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      invokee.pause();
-      invokee.currentTime = 0;
-      invokee.muted = false;
-    });
+    t.add_cleanup(resetState);
     assert_true(invokee.paused);
-    invokerbutton.setAttribute("invokeaction", "pause");
+    invokerbutton.setAttribute("command", "pause");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -193,17 +137,12 @@
   }, "invoking audio with pause action is a no-op");
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      invokee.pause();
-      invokee.currentTime = 0;
-      invokee.muted = false;
-    });
-    invokee.addEventListener("invoke", (e) => e.preventDefault(), {
+    t.add_cleanup(resetState);
+    invokee.addEventListener("command", (e) => e.preventDefault(), {
       once: true,
     });
     assert_true(invokee.paused);
-    invokerbutton.setAttribute("invokeaction", "pause");
+    invokerbutton.setAttribute("command", "pause");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -212,16 +151,11 @@
   }, "invoking audio with pause action and preventDefault is a no-op");
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      invokee.pause();
-      invokee.currentTime = 0;
-      invokee.muted = false;
-    });
+    t.add_cleanup(resetState);
     await test_driver.bless("play audio");
     invokee.play();
     assert_false(invokee.paused);
-    invokerbutton.setAttribute("invokeaction", "pause");
+    invokerbutton.setAttribute("command", "pause");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -232,14 +166,9 @@
   // mute
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      invokee.pause();
-      invokee.currentTime = 0;
-      invokee.muted = false;
-    });
+    t.add_cleanup(resetState);
     assert_false(invokee.muted);
-    invokerbutton.setAttribute("invokeaction", "toggleMuted");
+    invokerbutton.setAttribute("command", "toggleMuted");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -248,17 +177,12 @@
   }, "invoking audio with toggleMuted action mutes it");
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      invokee.pause();
-      invokee.currentTime = 0;
-      invokee.muted = false;
-    });
-    invokee.addEventListener("invoke", (e) => e.preventDefault(), {
+    t.add_cleanup(resetState);
+    invokee.addEventListener("command", (e) => e.preventDefault(), {
       once: true,
     });
     assert_false(invokee.muted);
-    invokerbutton.setAttribute("invokeaction", "toggleMuted");
+    invokerbutton.setAttribute("command", "toggleMuted");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -267,15 +191,10 @@
   }, "invoking audio with toggleMuted action and preventDefault is a no-op");
 
   promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      invokee.pause();
-      invokee.currentTime = 0;
-      invokee.muted = false;
-    });
+    t.add_cleanup(resetState);
     invokee.muted = true;
     assert_true(invokee.muted);
-    invokerbutton.setAttribute("invokeaction", "toggleMuted");
+    invokerbutton.setAttribute("command", "toggleMuted");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
diff --git a/tests/wpt/tests/html/semantics/invokers/invoketarget-on-audio-invalid-behavior.tentative.html b/tests/wpt/tests/html/semantics/invokers/invoketarget-on-audio-invalid-behavior.tentative.html
index 9e15ce38e85..3e18478a52f 100644
--- a/tests/wpt/tests/html/semantics/invokers/invoketarget-on-audio-invalid-behavior.tentative.html
+++ b/tests/wpt/tests/html/semantics/invokers/invoketarget-on-audio-invalid-behavior.tentative.html
@@ -11,11 +11,12 @@
 <script src="resources/invoker-utils.js"></script>
 
 <audio controls id="invokee" src="/media/sound_5.mp3"></audio>
-<button id="invokerbutton" invoketarget="invokee"></button>
+<button id="invokerbutton" commandfor="invokee"></button>
 
 <script>
   // invalid actions on audio
   [
+    "",
     "foo-bar",
     "showpopover",
     "showmodal",
@@ -24,8 +25,8 @@
     "close",
   ].forEach((action) => {
     promise_test(async function (t) {
-      t.add_cleanup(() => invokerbutton.removeAttribute("invokeaction"));
-      invokerbutton.setAttribute("invokeaction", action);
+      t.add_cleanup(() => invokerbutton.removeAttribute("command"));
+      invokerbutton.setAttribute("command", action);
       assert_true(invokee.paused);
       assert_false(invokee.muted);
       await clickOn(invokerbutton);
diff --git a/tests/wpt/tests/html/semantics/invokers/invoketarget-on-details-behavior.tentative.html b/tests/wpt/tests/html/semantics/invokers/invoketarget-on-details-behavior.tentative.html
index ad9b6caa57d..4c4998cf9d8 100644
--- a/tests/wpt/tests/html/semantics/invokers/invoketarget-on-details-behavior.tentative.html
+++ b/tests/wpt/tests/html/semantics/invokers/invoketarget-on-details-behavior.tentative.html
@@ -11,95 +11,83 @@
 <script src="resources/invoker-utils.js"></script>
 
 <details id="invokee">Details Contents</details>
-<button id="invokerbutton" invoketarget="invokee"></button>
+<button id="invokerbutton" commandfor="invokee" command="open"></button>
 
 <script>
   function resetState() {
-    invokerbutton.removeAttribute("invokeaction");
+    invokerbutton.removeAttribute("command");
     invokee.removeAttribute("open");
   }
 
   // Open actions
   [
-    null,
-    "",
     "toggle",
     "open",
     /* test case sensitivity */
     "tOgGlE",
     "oPeN",
-  ].forEach((action) => {
+  ].forEach((command) => {
     promise_test(
       async function (t) {
         t.add_cleanup(resetState);
-        if (action !== null) invokerbutton.invokeAction = action;
+        invokerbutton.command = command;
         assert_false(invokee.matches("[open]"));
         await clickOn(invokerbutton);
         assert_true(invokee.matches("[open]"));
       },
-      `invoking (as ${
-        action === null ? "auto" : action || "explicit empty"
-      }) closed details opens`,
+      `invoking (as ${command}) closed details opens`,
     );
 
     promise_test(
       async function (t) {
         t.add_cleanup(resetState);
-        if (action !== null) invokerbutton.invokeAction = action;
+        invokerbutton.command = command;
         assert_false(invokee.matches("[open]"));
-        invokee.addEventListener("invoke", (e) => e.preventDefault(), {
+        invokee.addEventListener("command", (e) => e.preventDefault(), {
           once: true,
         });
         await clickOn(invokerbutton);
         t.add_cleanup(() => invokee.removeAttribute("open"));
         assert_false(invokee.matches("[open]"));
       },
-      `invoking (as ${
-        action === null ? "auto" : action || "explicit empty"
-      }) closed details with preventDefault does not open`,
+      `invoking (as ${command}) closed details with preventDefault does not open`,
     );
   });
 
   // Close actions
   [
-    null,
-    "",
     "toggle",
     "close",
     /* test case sensitivity */
     "tOgGlE",
     "cLoSe",
-  ].forEach((action) => {
+  ].forEach((command) => {
     promise_test(
       async function (t) {
         t.add_cleanup(resetState);
-        if (action !== null) invokerbutton.invokeAction = action;
+        invokerbutton.command = command;
         invokee.setAttribute("open", "");
         assert_true(invokee.matches("[open]"));
         await clickOn(invokerbutton);
         assert_false(invokee.matches("[open]"));
       },
-      `invoking (as ${
-        action === null ? "auto" : action || "explicit empty"
-      }) open details closes`,
+      `invoking (as ${command}) open details closes`,
     );
 
     promise_test(
       async function (t) {
         t.add_cleanup(resetState);
-        if (action !== null) invokerbutton.invokeAction = action;
+        invokerbutton.command = command;
         invokee.setAttribute("open", "");
-        invokerbutton.setAttribute("invokeaction", "toggle");
-        invokee.addEventListener("invoke", (e) => e.preventDefault(), {
+        invokerbutton.setAttribute("command", "toggle");
+        invokee.addEventListener("command", (e) => e.preventDefault(), {
           once: true,
         });
         assert_true(invokee.matches("[open]"));
         await clickOn(invokerbutton);
         assert_true(invokee.matches("[open]"));
       },
-      `invoking (as ${
-        action === null ? "auto" : action || "explicit empty"
-      }) open details with prevent default closes`,
+      `invoking (as ${command}) open details with prevent default closes`,
     );
   });
 
@@ -107,9 +95,9 @@
 
   promise_test(async function (t) {
     t.add_cleanup(resetState);
-    invokerbutton.invokeAction = "toggle";
+    invokerbutton.command = "toggle";
     invokee.addEventListener(
-      "invoke",
+      "command",
       (e) => {
         invokee.setAttribute("open", "");
       },
@@ -126,20 +114,20 @@
 
   promise_test(async function (t) {
     t.add_cleanup(resetState);
-    invokerbutton.invokeAction = "open";
+    invokerbutton.command = "open";
     invokee.setAttribute("open", "");
     assert_true(invokee.matches("[open]"));
     await clickOn(invokerbutton);
     assert_true(invokee.matches("[open]"));
-  }, "invoking open details with open action is noop");
+  }, "invoking open details with open command is noop");
 
   // close
 
   promise_test(async function (t) {
     t.add_cleanup(resetState);
-    invokerbutton.invokeAction = "close";
+    invokerbutton.command = "close";
     assert_false(invokee.matches("[open]"));
     await clickOn(invokerbutton);
     assert_false(invokee.matches("[open]"));
-  }, "invoking closed details with close action is noop");
+  }, "invoking closed details with close command is noop");
 </script>
diff --git a/tests/wpt/tests/html/semantics/invokers/invoketarget-on-details-invalid-behavior.tentative.html b/tests/wpt/tests/html/semantics/invokers/invoketarget-on-details-invalid-behavior.tentative.html
index d5e90af9c0e..3a4e86e9f2c 100644
--- a/tests/wpt/tests/html/semantics/invokers/invoketarget-on-details-invalid-behavior.tentative.html
+++ b/tests/wpt/tests/html/semantics/invokers/invoketarget-on-details-invalid-behavior.tentative.html
@@ -11,16 +11,17 @@
 <script src="resources/invoker-utils.js"></script>
 
 <details id="invokee">Details Contents</details>
-<button id="invokerbutton" invoketarget="invokee"></button>
+<button id="invokerbutton" commandfor="invokee" command="open"></button>
 
 <script>
   function resetState() {
-    invokerbutton.removeAttribute("invokeaction");
+    invokerbutton.removeAttribute("command");
     invokee.removeAttribute("open");
   }
 
   // invalid actions on details
   [
+    "",
     "foo-bar",
     "showpopover",
     "showmodal",
@@ -28,22 +29,22 @@
     "hidepopover",
     "hide",
     "toggleopen",
-  ].forEach((action) => {
+  ].forEach((command) => {
     promise_test(async function (t) {
       t.add_cleanup(resetState);
-      invokerbutton.invokeAction = action;
+      invokerbutton.command = command;
       assert_false(invokee.matches("[open]"));
       await clickOn(invokerbutton);
       assert_false(invokee.matches("[open]"));
-    }, `invoking (as ${action}) on details does nothing`);
+    }, `invoking (as ${command}) on details does nothing`);
 
     promise_test(async function (t) {
       t.add_cleanup(resetState);
-      invokerbutton.invokeAction = action;
+      invokerbutton.command = command;
       invokee.setAttribute("open", "");
       assert_true(invokee.matches("[open]"));
       await clickOn(invokerbutton);
       assert_true(invokee.matches("[open]"));
-    }, `invoking (as ${action}) on open details does nothing`);
+    }, `invoking (as ${command}) on open details does nothing`);
   });
 </script>
diff --git a/tests/wpt/tests/html/semantics/invokers/invoketarget-on-dialog-behavior.tentative.html b/tests/wpt/tests/html/semantics/invokers/invoketarget-on-dialog-behavior.tentative.html
index 9f73e092b03..9cf1e530b3d 100644
--- a/tests/wpt/tests/html/semantics/invokers/invoketarget-on-dialog-behavior.tentative.html
+++ b/tests/wpt/tests/html/semantics/invokers/invoketarget-on-dialog-behavior.tentative.html
@@ -11,43 +11,39 @@
 <script src="resources/invoker-utils.js"></script>
 
 <dialog id="invokee">
-  <button id="containedinvoker" invoketarget="invokee"></button>
+  <button id="containedinvoker" commandfor="invokee" command="close"></button>
 </dialog>
-<button id="invokerbutton" invoketarget="invokee"></button>
+<button id="invokerbutton" commandfor="invokee" command="showmodal"></button>
 
 <script>
   function resetState() {
     invokee.close();
     try { invokee.hidePopover(); } catch {}
     invokee.removeAttribute("popover");
-    invokerbutton.removeAttribute("invokeaction");
-    containedinvoker.removeAttribute("invokeaction");
+    invokerbutton.setAttribute("command", "showmodal");
+    containedinvoker.setAttribute("command", "close");
   }
 
   // opening a dialog
 
-  [null, "", "showmodal", /* test case sensitivity */ "sHoWmOdAl"].forEach(
-    (action) => {
+  ["showmodal", /* test case sensitivity */ "sHoWmOdAl"].forEach(
+    (command) => {
       ["property", "attribute"].forEach((setType) => {
         promise_test(
           async function (t) {
             t.add_cleanup(resetState);
             assert_false(invokee.open, "invokee.open");
             assert_false(invokee.matches(":modal"), "invokee :modal");
-            if (typeof action === "string") {
-              if (setType === "property") {
-                invokerbutton.invokeaction = action;
-              } else {
-                invokerbutton.setAttribute("invokeaction", action);
-              }
+            if (setType === "property") {
+              invokerbutton.command = command;
+            } else {
+              invokerbutton.setAttribute("command", command);
             }
             await clickOn(invokerbutton);
             assert_true(invokee.open, "invokee.open");
             assert_true(invokee.matches(":modal"), "invokee :modal");
           },
-          `invoking (with invokeaction ${setType} as ${
-            action == null ? "auto" : action || "explicit empty"
-          }) closed dialog opens as modal`,
+          `invoking (with command ${setType} as ${command}) closed dialog opens as modal`,
         );
 
         promise_test(
@@ -55,23 +51,19 @@
             t.add_cleanup(resetState);
             assert_false(invokee.open, "invokee.open");
             assert_false(invokee.matches(":modal"), "invokee :modal");
-            invokee.addEventListener("invoke", (e) => e.preventDefault(), {
+            invokee.addEventListener("command", (e) => e.preventDefault(), {
               once: true,
             });
-            if (typeof action === "string") {
-              if (setType === "property") {
-                invokerbutton.invokeaction = action;
-              } else {
-                invokerbutton.setAttribute("invokeaction", action);
-              }
+            if (setType === "property") {
+              invokerbutton.command = command;
+            } else {
+              invokerbutton.setAttribute("command", command);
             }
             await clickOn(invokerbutton);
             assert_false(invokee.open, "invokee.open");
             assert_false(invokee.matches(":modal"), "invokee :modal");
           },
-          `invoking (with invokeaction ${setType} as ${
-            action == null ? "auto" : action || "explicit empty"
-          }) closed dialog with preventDefault is noop`,
+          `invoking (with command ${setType} as ${command}) closed dialog with preventDefault is noop`,
         );
 
         promise_test(
@@ -80,26 +72,22 @@
             assert_false(invokee.open, "invokee.open");
             assert_false(invokee.matches(":modal"), "invokee :modal");
             invokee.addEventListener(
-              "invoke",
+              "command",
               (e) => {
-                invokerbutton.setAttribute("invokeaction", "close");
+                invokerbutton.setAttribute("command", "close");
               },
               { once: true },
             );
-            if (typeof action === "string") {
-              if (setType === "property") {
-                invokerbutton.invokeaction = action;
-              } else {
-                invokerbutton.setAttribute("invokeaction", action);
-              }
+            if (setType === "property") {
+              invokerbutton.command = command;
+            } else {
+              invokerbutton.setAttribute("command", command);
             }
             await clickOn(invokerbutton);
             assert_true(invokee.open, "invokee.open");
             assert_true(invokee.matches(":modal"), "invokee :modal");
           },
-          `invoking (with invokeaction ${setType} as ${
-            action == null ? "auto" : action || "explicit empty"
-          }) while changing action still opens as modal`,
+          `invoking (with command ${setType} as ${command}) while changing command still opens as modal`,
         );
       });
     },
@@ -107,7 +95,7 @@
 
   // closing an already open dialog
 
-  [null, "", "close", /* test case sensitivity */ "cLoSe"].forEach((action) => {
+  ["close", /* test case sensitivity */ "cLoSe"].forEach((command) => {
     ["property", "attribute"].forEach((setType) => {
       promise_test(
         async function (t) {
@@ -115,20 +103,16 @@
           invokee.show();
           assert_true(invokee.open, "invokee.open");
           assert_false(invokee.matches(":modal"), "invokee :modal");
-          if (typeof action === "string") {
-            if (setType === "property") {
-              containedinvoker.invokeaction = action;
-            } else {
-              containedinvoker.setAttribute("invokeaction", action);
-            }
+          if (setType === "property") {
+            containedinvoker.command = command;
+          } else {
+            containedinvoker.setAttribute("command", command);
           }
           await clickOn(containedinvoker);
           assert_false(invokee.open, "invokee.open");
           assert_false(invokee.matches(":modal"), "invokee :modal");
         },
-        `invoking to close (with invokeaction ${setType} as ${
-          action == null ? "auto" : action || "explicit empty"
-        }) open dialog closes`,
+        `invoking to close (with command ${setType} as ${command}) open dialog closes`,
       );
 
       promise_test(
@@ -137,23 +121,21 @@
           invokee.show();
           assert_true(invokee.open, "invokee.open");
           assert_false(invokee.matches(":modal"), "invokee :modal");
-          if (typeof action === "string") {
+          if (typeof command === "string") {
             if (setType === "property") {
-              containedinvoker.invokeaction = action;
+              containedinvoker.command = command;
             } else {
-              containedinvoker.setAttribute("invokeaction", action);
+              containedinvoker.setAttribute("command", command);
             }
           }
-          invokee.addEventListener("invoke", (e) => e.preventDefault(), {
+          invokee.addEventListener("command", (e) => e.preventDefault(), {
             once: true,
           });
           await clickOn(containedinvoker);
           assert_true(invokee.open, "invokee.open");
           assert_false(invokee.matches(":modal"), "invokee :modal");
         },
-        `invoking to close (with invokeaction ${setType} as ${
-          action == null ? "auto" : action || "explicit empty"
-        }) open dialog with preventDefault is no-op`,
+        `invoking to close (with command ${setType} as ${command}) open dialog with preventDefault is no-op`,
       );
 
       promise_test(
@@ -162,23 +144,19 @@
           invokee.showModal();
           assert_true(invokee.open, "invokee.open");
           assert_true(invokee.matches(":modal"), "invokee :modal");
-          if (typeof action === "string") {
-            if (setType === "property") {
-              containedinvoker.invokeaction = action;
-            } else {
-              containedinvoker.setAttribute("invokeaction", action);
-            }
+          if (setType === "property") {
+            containedinvoker.command = command;
+          } else {
+            containedinvoker.setAttribute("command", command);
           }
-          invokee.addEventListener("invoke", (e) => e.preventDefault(), {
+          invokee.addEventListener("command", (e) => e.preventDefault(), {
             once: true,
           });
           await clickOn(containedinvoker);
           assert_true(invokee.open, "invokee.open");
           assert_true(invokee.matches(":modal"), "invokee :modal");
         },
-        `invoking to close (with invokeaction ${setType} as ${
-          action == null ? "auto" : action || "explicit empty"
-        }) open modal dialog with preventDefault is no-op`,
+        `invoking to close (with command ${setType} as ${command}) open modal dialog with preventDefault is no-op`,
       );
 
       promise_test(
@@ -187,17 +165,15 @@
           invokee.show();
           assert_true(invokee.open, "invokee.open");
           assert_false(invokee.matches(":modal"), "invokee :modal");
-          if (typeof action === "string") {
-            if (setType === "property") {
-              containedinvoker.invokeaction = action;
-            } else {
-              containedinvoker.setAttribute("invokeaction", action);
-            }
+          if (setType === "property") {
+            containedinvoker.command = command;
+          } else {
+            containedinvoker.setAttribute("command", command);
           }
           invokee.addEventListener(
-            "invoke",
+            "command",
             (e) => {
-              containedinvoker.setAttribute("invokeaction", "show");
+              containedinvoker.setAttribute("command", "show");
             },
             { once: true },
           );
@@ -205,9 +181,7 @@
           assert_false(invokee.open, "invokee.open");
           assert_false(invokee.matches(":modal"), "invokee :modal");
         },
-        `invoking to close (with invokeaction ${setType} as ${
-          action == null ? "auto" : action || "explicit empty"
-        }) open dialog while changing action still closes`,
+        `invoking to close (with command ${setType} as ${command}) open dialog while changing command still closes`,
       );
 
       promise_test(
@@ -216,17 +190,15 @@
           invokee.showModal();
           assert_true(invokee.open, "invokee.open");
           assert_true(invokee.matches(":modal"), "invokee :modal");
-          if (typeof action === "string") {
-            if (setType === "property") {
-              containedinvoker.invokeaction = action;
-            } else {
-              containedinvoker.setAttribute("invokeaction", action);
-            }
+          if (setType === "property") {
+            containedinvoker.command = command;
+          } else {
+            containedinvoker.setAttribute("command", command);
           }
           invokee.addEventListener(
-            "invoke",
+            "command",
             (e) => {
-              containedinvoker.setAttribute("invokeaction", "show");
+              containedinvoker.setAttribute("command", "show");
             },
             { once: true },
           );
@@ -234,9 +206,7 @@
           assert_false(invokee.open, "invokee.open");
           assert_false(invokee.matches(":modal"), "invokee :modal");
         },
-        `invoking to close (with invokeaction ${setType} as ${
-          action == null ? "auto" : action || "explicit empty"
-        }) open modal dialog while changing action still closes`,
+        `invoking to close (with command ${setType} as ${command}) open modal dialog while changing command still closes`,
       );
     });
   });
@@ -245,7 +215,7 @@
 
   promise_test(async function (t) {
     t.add_cleanup(resetState);
-    containedinvoker.setAttribute("invokeaction", "showModal");
+    containedinvoker.setAttribute("command", "showModal");
     invokee.show();
     assert_true(invokee.open, "invokee.open");
     assert_false(invokee.matches(":modal"), "invokee :modal");
@@ -256,25 +226,25 @@
 
   promise_test(async function (t) {
     t.add_cleanup(resetState);
-    containedinvoker.setAttribute("invokeaction", "showmodal");
+    containedinvoker.setAttribute("command", "showmodal");
     invokee.showModal();
     assert_true(invokee.open, "invokee.open");
     assert_true(invokee.matches(":modal"), "invokee :modal");
     invokee.addEventListener(
-      "invoke",
+      "command",
       (e) => {
-        containedinvoker.setAttribute("invokeaction", "close");
+        containedinvoker.setAttribute("command", "close");
       },
       { once: true },
     );
     await clickOn(invokerbutton);
     assert_true(invokee.open, "invokee.open");
     assert_true(invokee.matches(":modal"), "invokee :modal");
-  }, "invoking (as showmodal) open modal, while changing action still a no-op");
+  }, "invoking (as showmodal) open modal, while changing command still a no-op");
 
   promise_test(async function (t) {
     t.add_cleanup(resetState);
-    invokerbutton.setAttribute("invokeaction", "showmodal");
+    invokerbutton.setAttribute("command", "showmodal");
     assert_false(invokee.open, "invokee.open");
     assert_false(invokee.matches(":modal"), "invokee :modal");
     invokee.setAttribute("popover", "auto");
@@ -287,7 +257,7 @@
 
   promise_test(async function (t) {
     t.add_cleanup(resetState);
-    invokerbutton.setAttribute("invokeaction", "close");
+    invokerbutton.setAttribute("command", "close");
     assert_false(invokee.open, "invokee.open");
     assert_false(invokee.matches(":modal"), "invokee :modal");
     await clickOn(containedinvoker);
@@ -296,21 +266,21 @@
   }, "invoking (as close) already closed dialog is noop");
 
   // Open Popovers using Dialog actions
-  ["showmodal", "close", ""].forEach((action) => {
+  ["showmodal", "close"].forEach((command) => {
     ["manual", "auto"].forEach((popoverState) => {
       promise_test(
         async function (t) {
           t.add_cleanup(resetState);
           invokee.setAttribute("popover", popoverState);
           invokee.showPopover();
-          containedinvoker.setAttribute("invokeaction", action);
+          containedinvoker.setAttribute("command", command);
           assert_true(
             invokee.matches(":popover-open"),
             "invokee :popover-open",
           );
           assert_false(invokee.open, "invokee.open");
           assert_false(invokee.matches(":modal"), "invokee :modal");
-          invokee.addEventListener("invoke", (e) => e.preventDefault(), {
+          invokee.addEventListener("command", (e) => e.preventDefault(), {
             once: true,
           });
           await clickOn(containedinvoker);
@@ -321,15 +291,13 @@
           assert_false(invokee.open, "invokee.open");
           assert_false(invokee.matches(":modal"), "invokee :modal");
         },
-        `invoking (as ${
-          action || "explicit empty"
-        }) dialog as open popover=${popoverState} is noop`,
+        `invoking (as ${command}) dialog as open popover=${popoverState} is noop`,
       );
     });
   });
 
   // Elements being disconnected during invoke steps
-  ["showmodal", "close", ""].forEach((action) => {
+  ["showmodal", "close"].forEach((command) => {
     promise_test(
       async function (t) {
         t.add_cleanup(() => {
@@ -337,11 +305,11 @@
           resetState();
         });
         const invokee = document.querySelector("#invokee");
-        invokerbutton.setAttribute("invokeaction", action);
+        invokerbutton.setAttribute("command", command);
         assert_false(invokee.open, "invokee.open");
         assert_false(invokee.matches(":modal"), "invokee :modal");
         invokee.addEventListener(
-          "invoke",
+          "command",
           (e) => {
             invokee.remove();
           },
@@ -353,42 +321,36 @@
         assert_false(invokee.open, "invokee.open");
         assert_false(invokee.matches(":modal"), "invokee :modal");
       },
-      `invoking (as ${
-        action || "explicit empty"
-      }) dialog that is removed is noop`,
+      `invoking (as ${command}) dialog that is removed is noop`,
     );
 
     promise_test(
       async function (t) {
         const invokerbutton = document.createElement("button");
-        invokerbutton.invokeTargetElement = invokee;
-        invokerbutton.setAttribute("invokeaction", action);
+        invokerbutton.commandForElement = invokee;
+        invokerbutton.setAttribute("command", command);
         assert_false(invokee.open, "invokee.open");
         assert_false(invokee.matches(":modal"), "invokee :modal");
         await clickOn(invokerbutton);
         assert_false(invokee.open, "invokee.open");
         assert_false(invokee.matches(":modal"), "invokee :modal");
       },
-      `invoking (as ${
-        action || "explicit empty"
-      }) dialog from a detached invoker`,
+      `invoking (as ${command}) dialog from a detached invoker`,
     );
 
     promise_test(
       async function (t) {
         const invokerbutton = document.createElement("button");
         const invokee = document.createElement("dialog");
-        invokerbutton.invokeTargetElement = invokee;
-        invokerbutton.setAttribute("invokeaction", action);
+        invokerbutton.commandForElementt = invokee;
+        invokerbutton.setAttribute("command", command);
         assert_false(invokee.open, "invokee.open");
         assert_false(invokee.matches(":modal"), "invokee :modal");
         await clickOn(invokerbutton);
         assert_false(invokee.open, "invokee.open");
         assert_false(invokee.matches(":modal"), "invokee :modal");
       },
-      `invoking (as ${
-        action || "explicit empty"
-      }) detached dialog from a detached invoker`,
+      `invoking (as ${command}) detached dialog from a detached invoker`,
     );
   });
 </script>
diff --git a/tests/wpt/tests/html/semantics/invokers/invoketarget-on-dialog-invalid-behavior.tentative.html b/tests/wpt/tests/html/semantics/invokers/invoketarget-on-dialog-invalid-behavior.tentative.html
index af84c22594a..8ea5066dd74 100644
--- a/tests/wpt/tests/html/semantics/invokers/invoketarget-on-dialog-invalid-behavior.tentative.html
+++ b/tests/wpt/tests/html/semantics/invokers/invoketarget-on-dialog-invalid-behavior.tentative.html
@@ -11,21 +11,22 @@
 <script src="resources/invoker-utils.js"></script>
 
 <dialog id="invokee">
-  <button id="containedinvoker" invoketarget="invokee"></button>
+  <button id="containedinvoker" commandfor="invokee" command="close"></button>
 </dialog>
-<button id="invokerbutton" invoketarget="invokee"></button>
+<button id="invokerbutton" commandfor="invokee" command="showmodal"></button>
 
 <script>
   function resetState() {
     invokee.close();
     try { invokee.hidePopover(); } catch {}
     invokee.removeAttribute("popover");
-    invokerbutton.removeAttribute("invokeaction");
-    containedinvoker.removeAttribute("invokeaction");
+    invokerbutton.removeAttribute("command");
+    containedinvoker.removeAttribute("command");
   }
 
   // invalid
   [
+    "",
     "foo",
     "foo-bar",
     "auto",
@@ -36,7 +37,7 @@
   ].forEach((action) => {
     promise_test(async function (t) {
       t.add_cleanup(resetState);
-      invokerbutton.setAttribute("invokeaction", action);
+      invokerbutton.setAttribute("command", action);
       assert_false(invokee.open, "invokee.open");
       assert_false(invokee.matches(":modal"), "invokee :modal");
       await clickOn(invokerbutton);
@@ -46,7 +47,7 @@
 
     promise_test(async function (t) {
       t.add_cleanup(resetState);
-      containedinvoker.setAttribute("invokeaction", action);
+      containedinvoker.setAttribute("command", action);
       invokee.show();
       assert_true(invokee.open, "invokee.open");
       assert_false(invokee.matches(":modal"), "invokee :modal");
@@ -57,7 +58,7 @@
 
     promise_test(async function (t) {
       t.add_cleanup(resetState);
-      containedinvoker.setAttribute("invokeaction", action);
+      containedinvoker.setAttribute("command", action);
       invokee.showModal();
       assert_true(invokee.open, "invokee.open");
       assert_true(invokee.matches(":modal"), "invokee :modal");
@@ -68,14 +69,14 @@
 
     promise_test(async function (t) {
       t.add_cleanup(resetState);
-      containedinvoker.setAttribute("invokeaction", action);
+      containedinvoker.setAttribute("command", action);
       invokee.showModal();
       assert_true(invokee.open, "invokee.open");
       assert_true(invokee.matches(":modal"), "invokee :modal");
       invokee.addEventListener(
-        "invoke",
+        "command",
         (e) => {
-          containedinvoker.setAttribute("invokeaction", "");
+          containedinvoker.setAttribute("command", "");
         },
         { once: true },
       );
@@ -86,21 +87,21 @@
   });
 
   // Open Popovers using Dialog actions
-  ["showmodal", "close", ""].forEach((action) => {
+  ["showmodal", "close"].forEach((action) => {
     ["manual", "auto"].forEach((popoverState) => {
       promise_test(
         async function (t) {
           t.add_cleanup(resetState);
           invokee.setAttribute("popover", popoverState);
           invokee.showPopover();
-          containedinvoker.setAttribute("invokeaction", action);
+          containedinvoker.setAttribute("command", action);
           assert_true(
             invokee.matches(":popover-open"),
             "invokee :popover-open",
           );
           assert_false(invokee.open, "invokee.open");
           assert_false(invokee.matches(":modal"), "invokee :modal");
-          invokee.addEventListener("invoke", (e) => e.preventDefault(), {
+          invokee.addEventListener("command", (e) => e.preventDefault(), {
             once: true,
           });
           await clickOn(containedinvoker);
diff --git a/tests/wpt/tests/html/semantics/invokers/invoketarget-on-input-number.tentative.html b/tests/wpt/tests/html/semantics/invokers/invoketarget-on-input-number.tentative.html
index b06053b9f1f..643423131eb 100644
--- a/tests/wpt/tests/html/semantics/invokers/invoketarget-on-input-number.tentative.html
+++ b/tests/wpt/tests/html/semantics/invokers/invoketarget-on-input-number.tentative.html
@@ -10,12 +10,12 @@
 <script src="resources/invoker-utils.js"></script>
 
 <input type="number" id="invokee" value="0">
-<button id="invokerbutton" invoketarget="invokee"></button>
+<button id="invokerbutton" commandfor="invokee"></button>
 
 <script>
   function reset() {
     invokee.value = 0;
-    invokerbutton.removeAttribute('invokeaction');
+    invokerbutton.removeAttribute('command');
   }
 
   // stepUp
@@ -23,7 +23,7 @@
   promise_test(async function (t) {
     t.add_cleanup(reset);
     assert_equals(invokee.valueAsNumber, 0);
-    invokerbutton.setAttribute("invokeaction", "stepup");
+    invokerbutton.setAttribute("command", "stepup");
     await clickOn(invokerbutton);
     assert_equals(invokee.valueAsNumber, 1);
   }, "invoking number input with stepup action increments value");
@@ -31,7 +31,7 @@
   promise_test(async function (t) {
     t.add_cleanup(reset);
     assert_equals(invokee.valueAsNumber, 0);
-    invokerbutton.setAttribute("invokeaction", "sTePuP");
+    invokerbutton.setAttribute("command", "sTePuP");
     await clickOn(invokerbutton);
     assert_equals(invokee.valueAsNumber, 1);
   }, "invoking number input with stepup action (case-insensitive) increments value");
@@ -39,8 +39,8 @@
   promise_test(async function (t) {
     t.add_cleanup(reset);
     assert_equals(invokee.valueAsNumber, 0);
-    invokerbutton.setAttribute("invokeaction", "stepup");
-    invokee.addEventListener("invoke", (e) => e.preventDefault(), {
+    invokerbutton.setAttribute("command", "stepup");
+    invokee.addEventListener("command", (e) => e.preventDefault(), {
       once: true,
     });
     await clickOn(invokerbutton);
@@ -52,7 +52,7 @@
   promise_test(async function (t) {
     t.add_cleanup(reset);
     assert_equals(invokee.valueAsNumber, 0);
-    invokerbutton.setAttribute("invokeaction", "stepdown");
+    invokerbutton.setAttribute("command", "stepdown");
     await clickOn(invokerbutton);
     assert_equals(invokee.valueAsNumber, -1);
   }, "invoking number input with stepdown action decrements value");
@@ -60,7 +60,7 @@
   promise_test(async function (t) {
     t.add_cleanup(reset);
     assert_equals(invokee.valueAsNumber, 0);
-    invokerbutton.setAttribute("invokeaction", "sTePdOwN");
+    invokerbutton.setAttribute("command", "sTePdOwN");
     await clickOn(invokerbutton);
     assert_equals(invokee.valueAsNumber, -1);
   }, "invoking number input with stepdown action (case-insensitive) decrements value");
@@ -68,8 +68,8 @@
   promise_test(async function (t) {
     t.add_cleanup(reset);
     assert_equals(invokee.valueAsNumber, 0);
-    invokerbutton.setAttribute("invokeaction", "stepdown");
-    invokee.addEventListener("invoke", (e) => e.preventDefault(), {
+    invokerbutton.setAttribute("command", "stepdown");
+    invokee.addEventListener("command", (e) => e.preventDefault(), {
       once: true,
     });
     await clickOn(invokerbutton);
diff --git a/tests/wpt/tests/html/semantics/invokers/invoketarget-on-popover-behavior.tentative.html b/tests/wpt/tests/html/semantics/invokers/invoketarget-on-popover-behavior.tentative.html
index f414559e55a..c974b6ff108 100644
--- a/tests/wpt/tests/html/semantics/invokers/invoketarget-on-popover-behavior.tentative.html
+++ b/tests/wpt/tests/html/semantics/invokers/invoketarget-on-popover-behavior.tentative.html
@@ -11,135 +11,133 @@
 <script src="resources/invoker-utils.js"></script>
 
 <div id="invokee" popover>
-  <button id="containedinvoker" invoketarget="invokee"></button>
+  <button id="containedinvoker" commandfor="invokee" command="hidepopover"></button>
 </div>
-<button id="invokerbutton" invoketarget="invokee"></button>
+<button id="invokerbutton" commandfor="invokee" command="togglepopover"></button>
 
 <script>
-  // auto
-
-  promise_test(async function (t) {
-    assert_false(invokee.matches(":popover-open"));
-    invokee.addEventListener("invoke", (e) => { invokerbutton.setAttribute('invokeaction', 'hidepopover'); }, {
-      once: true,
-    });
-    await clickOn(invokerbutton);
-    t.add_cleanup(() => {
-      invokee.hidePopover();
-      invokerbutton.removeAttribute("invokeaction");
-    });
-    assert_true(invokee.matches(":popover-open"));
-  }, "changing invokeaction attribute inside invokeevent doesn't impact the invocation");
-
   function resetState() {
-    invokerbutton.removeAttribute("invokeaction");
-    containedinvoker.removeAttribute("invokeaction");
+    invokerbutton.setAttribute("commandfor", "invokee");
+    invokerbutton.setAttribute("command", "togglepopover");
+    containedinvoker.setAttribute("commandfor", "invokee");
+    containedinvoker.setAttribute("command", "closepopover");
     try {
       invokee.hidePopover();
     } catch {}
     invokee.setAttribute("popover", "");
   }
 
+  promise_test(async function (t) {
+    assert_false(invokee.matches(":popover-open"));
+    invokee.addEventListener("command", (e) => { invokerbutton.setAttribute('command', 'hidepopover'); }, {
+      once: true,
+    });
+    await clickOn(invokerbutton);
+    t.add_cleanup(resetState);
+    assert_true(invokee.matches(":popover-open"));
+  }, "changing command attribute inside invokeevent doesn't impact the invocation");
+
   // Open actions
   [
-    null,
-    "",
     "togglepopover",
     "showpopover",
     /* test case sensitivity */
     "tOgGlEpOpOvEr",
     "sHoWpOpOvEr",
-  ].forEach((action) => {
+  ].forEach((command) => {
     promise_test(
       async function (t) {
         t.add_cleanup(resetState);
-        if (action !== null) invokerbutton.invokeAction = action;
+        invokerbutton.command = command;
         assert_false(invokee.matches(":popover-open"));
         await clickOn(invokerbutton);
         assert_true(invokee.matches(":popover-open"));
       },
-      `invoking (as ${
-        action === null ? "auto" : action || "explicit empty"
-      }) closed popover opens`,
+      `invoking (as ${command}) closed popover opens`,
     );
 
     promise_test(
       async function (t) {
         t.add_cleanup(resetState);
-        if (action !== null) invokerbutton.invokeAction = action;
+        invokerbutton.command = command;
         assert_false(invokee.matches(":popover-open"));
-        invokee.addEventListener("invoke", (e) => e.preventDefault(), {
+        invokee.addEventListener("command", (e) => e.preventDefault(), {
           once: true,
         });
         await clickOn(invokerbutton);
         assert_false(invokee.matches(":popover-open"));
       },
-      `invoking (as ${
-        action === null ? "auto" : action || "explicit empty"
-      }) closed popover with preventDefault does not open`,
+      `invoking (as ${command}) closed popover with preventDefault does not open`,
     );
   });
 
   // Close actions
   [
-    null,
-    "",
     "togglepopover",
     "hidepopover",
     /* test case sensitivity */
     "tOgGlEpOpOvEr",
     "hIdEpOpOvEr",
-  ].forEach((action) => {
+  ].forEach((command) => {
     promise_test(
       async function (t) {
         t.add_cleanup(resetState);
-        if (action !== null) invokerbutton.invokeAction = action;
+        invokerbutton.command = command;
         invokee.showPopover();
         assert_true(invokee.matches(":popover-open"));
         await clickOn(invokerbutton);
         assert_false(invokee.matches(":popover-open"));
       },
-      `invoking (as ${
-        action === null ? "auto" : action || "explicit empty"
-      }) open popover closes`,
+      `invoking (as ${command}) open popover closes`,
     );
 
     promise_test(
       async function (t) {
         t.add_cleanup(resetState);
-        if (action !== null) containedinvoker.invokeAction = action;
+        invokerbutton.command = command;
+        invokee.showPopover();
+        assert_true(invokee.matches(":popover-open"));
+        invokee.addEventListener("command", (e) => e.preventDefault(), {
+          once: true,
+        });
+        await clickOn(invokerbutton);
+        assert_true(invokee.matches(":popover-open"));
+      },
+      `invoking (as ${command}) open popover with preventDefault does not close`,
+    );
+
+    promise_test(
+      async function (t) {
+        t.add_cleanup(resetState);
+        containedinvoker.command = command;
         invokee.showPopover();
         assert_true(invokee.matches(":popover-open"));
         await clickOn(containedinvoker);
         assert_false(invokee.matches(":popover-open"));
       },
-      `invoking (as ${
-        action === null ? "auto" : action || "explicit empty"
-      }) from within open popover closes`,
+      `invoking (as ${command}) from within open popover closes`,
     );
 
     promise_test(
       async function (t) {
         t.add_cleanup(resetState);
-        if (action !== null) invcontainedinvokervokeaction = action;
+        containedinvoker.command = command;
         invokee.showPopover();
-        invokee.addEventListener("invoke", (e) => e.preventDefault(), {
+        invokee.addEventListener("command", (e) => e.preventDefault(), {
           once: true,
         });
         assert_true(invokee.matches(":popover-open"));
         await clickOn(containedinvoker);
         assert_true(invokee.matches(":popover-open"));
       },
-      `invoking (as ${
-        action === null ? "auto" : action || "explicit empty"
-      }) open popover with preventDefault does not close`,
+      `invoking (as ${command}) from within open popover with preventDefault does not close`,
     );
   });
 
   // showpopover specific
   promise_test(async function (t) {
     t.add_cleanup(resetState);
-    invokerbutton.setAttribute("invokeaction", "showpopover");
+    invokerbutton.setAttribute("command", "showpopover");
     invokee.showPopover();
     assert_true(invokee.matches(":popover-open"));
     await clickOn(invokerbutton);
@@ -149,7 +147,7 @@
   // hidepopover specific
   promise_test(async function (t) {
     t.add_cleanup(resetState);
-    invokerbutton.setAttribute("invokeaction", "hidepopover");
+    invokerbutton.setAttribute("command", "hidepopover");
     assert_false(invokee.matches(":popover-open"));
     await clickOn(invokerbutton);
     assert_false(invokee.matches(":popover-open"));
diff --git a/tests/wpt/tests/html/semantics/invokers/invoketarget-on-popover-invalid-behavior.tentative.html b/tests/wpt/tests/html/semantics/invokers/invoketarget-on-popover-invalid-behavior.tentative.html
index 755f3a67770..31442261f37 100644
--- a/tests/wpt/tests/html/semantics/invokers/invoketarget-on-popover-invalid-behavior.tentative.html
+++ b/tests/wpt/tests/html/semantics/invokers/invoketarget-on-popover-invalid-behavior.tentative.html
@@ -11,14 +11,14 @@
 <script src="resources/invoker-utils.js"></script>
 
 <div id="invokee" popover>
-  <button id="containedinvoker" invoketarget="invokee"></button>
+  <button id="containedinvoker" commandfor="invokee"></button>
 </div>
-<button id="invokerbutton" invoketarget="invokee"></button>
+<button id="invokerbutton" commandfor="invokee"></button>
 
 <script>
   function resetState() {
-    invokerbutton.removeAttribute("invokeaction");
-    containedinvoker.removeAttribute("invokeaction");
+    invokerbutton.removeAttribute("command");
+    containedinvoker.removeAttribute("command");
     try {
       invokee.hidePopover();
     } catch {}
@@ -26,22 +26,22 @@
   }
 
   // invalid actions on showpopover
-  ["foo-bar", "showmodal", "showpicker", "open", "close"].forEach((action) => {
+  [null, "", "foo-bar", "showmodal", "showpicker", "open", "close"].forEach((command) => {
     promise_test(async function (t) {
       t.add_cleanup(resetState);
-      invokerbutton.invokeAction = action;
+      invokerbutton.command = command;
       assert_false(invokee.matches(":popover-open"));
       await clickOn(invokerbutton);
       assert_false(invokee.matches(":popover-open"));
-    }, `invoking (as ${action}) on popover does nothing`);
+    }, `invoking (as ${command}) on popover does nothing`);
 
     promise_test(async function (t) {
       t.add_cleanup(resetState);
-      invokerbutton.invokeAction = action;
+      invokerbutton.command = command;
       invokee.showPopover();
       assert_true(invokee.matches(":popover-open"));
       await clickOn(invokerbutton);
       assert_true(invokee.matches(":popover-open"));
-    }, `invoking (as ${action}) on open popover does nothing`);
+    }, `invoking (as ${command}) on open popover does nothing`);
   });
 </script>
diff --git a/tests/wpt/tests/html/semantics/invokers/invoketarget-on-video-behavior.tentative.html b/tests/wpt/tests/html/semantics/invokers/invoketarget-on-video-behavior.tentative.html
index d15d6f95841..e395281ee31 100644
--- a/tests/wpt/tests/html/semantics/invokers/invoketarget-on-video-behavior.tentative.html
+++ b/tests/wpt/tests/html/semantics/invokers/invoketarget-on-video-behavior.tentative.html
@@ -11,38 +11,20 @@
 <script src="resources/invoker-utils.js"></script>
 
 <video controls id="invokee" src="/media/movie_5.mp4"></video>
-<button id="invokerbutton" invoketarget="invokee"></button>
+<button id="invokerbutton" commandfor="invokee"></button>
 
 <script>
-  // auto
-
-  promise_test(async function (t) {
-    t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
-      invokee.pause();
-      invokee.currentTime = 0;
-      invokee.muted = false;
-    });
-    assert_true(invokee.paused);
-    invokerbutton.setAttribute("invokeaction", "");
-    await clickOn(invokerbutton);
-    await new Promise((resolve) => {
-      requestAnimationFrame(resolve);
-    });
-    assert_true(invokee.paused);
-  }, "invoking video with auto action is no-op");
-
   // playpause
 
   promise_test(async function (t) {
     t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
+      invokerbutton.removeAttribute("command");
       invokee.pause();
       invokee.currentTime = 0;
       invokee.muted = false;
     });
     assert_true(invokee.paused);
-    invokerbutton.setAttribute("invokeaction", "playpause");
+    invokerbutton.setAttribute("command", "playpause");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -52,16 +34,16 @@
 
   promise_test(async function (t) {
     t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
+      invokerbutton.removeAttribute("command");
       invokee.pause();
       invokee.currentTime = 0;
       invokee.muted = false;
     });
-    invokee.addEventListener("invoke", (e) => e.preventDefault(), {
+    invokee.addEventListener("command", (e) => e.preventDefault(), {
       once: true,
     });
     assert_true(invokee.paused);
-    invokerbutton.setAttribute("invokeaction", "playpause");
+    invokerbutton.setAttribute("command", "playpause");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -71,7 +53,7 @@
 
   promise_test(async function (t) {
     t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
+      invokerbutton.removeAttribute("command");
       invokee.pause();
       invokee.currentTime = 0;
       invokee.muted = false;
@@ -79,7 +61,7 @@
     await test_driver.bless("play video");
     invokee.play();
     assert_false(invokee.paused);
-    invokerbutton.setAttribute("invokeaction", "playpause");
+    invokerbutton.setAttribute("command", "playpause");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -91,13 +73,13 @@
 
   promise_test(async function (t) {
     t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
+      invokerbutton.removeAttribute("command");
       invokee.pause();
       invokee.currentTime = 0;
       invokee.muted = false;
     });
     assert_true(invokee.paused);
-    invokerbutton.setAttribute("invokeaction", "play");
+    invokerbutton.setAttribute("command", "play");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -107,16 +89,16 @@
 
   promise_test(async function (t) {
     t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
+      invokerbutton.removeAttribute("command");
       invokee.pause();
       invokee.currentTime = 0;
       invokee.muted = false;
     });
-    invokee.addEventListener("invoke", (e) => e.preventDefault(), {
+    invokee.addEventListener("command", (e) => e.preventDefault(), {
       once: true,
     });
     assert_true(invokee.paused);
-    invokerbutton.setAttribute("invokeaction", "play");
+    invokerbutton.setAttribute("command", "play");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -126,7 +108,7 @@
 
   promise_test(async function (t) {
     t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
+      invokerbutton.removeAttribute("command");
       invokee.pause();
       invokee.currentTime = 0;
       invokee.muted = false;
@@ -134,7 +116,7 @@
     await test_driver.bless("play video");
     invokee.play();
     assert_false(invokee.paused);
-    invokerbutton.setAttribute("invokeaction", "play");
+    invokerbutton.setAttribute("command", "play");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -146,13 +128,13 @@
 
   promise_test(async function (t) {
     t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
+      invokerbutton.removeAttribute("command");
       invokee.pause();
       invokee.currentTime = 0;
       invokee.muted = false;
     });
     assert_true(invokee.paused);
-    invokerbutton.setAttribute("invokeaction", "pause");
+    invokerbutton.setAttribute("command", "pause");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -162,16 +144,16 @@
 
   promise_test(async function (t) {
     t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
+      invokerbutton.removeAttribute("command");
       invokee.pause();
       invokee.currentTime = 0;
       invokee.muted = false;
     });
-    invokee.addEventListener("invoke", (e) => e.preventDefault(), {
+    invokee.addEventListener("command", (e) => e.preventDefault(), {
       once: true,
     });
     assert_true(invokee.paused);
-    invokerbutton.setAttribute("invokeaction", "pause");
+    invokerbutton.setAttribute("command", "pause");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -181,7 +163,7 @@
 
   promise_test(async function (t) {
     t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
+      invokerbutton.removeAttribute("command");
       invokee.pause();
       invokee.currentTime = 0;
       invokee.muted = false;
@@ -189,7 +171,7 @@
     await test_driver.bless("play video");
     invokee.play();
     assert_false(invokee.paused);
-    invokerbutton.setAttribute("invokeaction", "pause");
+    invokerbutton.setAttribute("command", "pause");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -201,13 +183,13 @@
 
   promise_test(async function (t) {
     t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
+      invokerbutton.removeAttribute("command");
       invokee.pause();
       invokee.currentTime = 0;
       invokee.muted = false;
     });
     assert_false(invokee.muted);
-    invokerbutton.setAttribute("invokeaction", "toggleMuted");
+    invokerbutton.setAttribute("command", "toggleMuted");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -217,16 +199,16 @@
 
   promise_test(async function (t) {
     t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
+      invokerbutton.removeAttribute("command");
       invokee.pause();
       invokee.currentTime = 0;
       invokee.muted = false;
     });
-    invokee.addEventListener("invoke", (e) => e.preventDefault(), {
+    invokee.addEventListener("command", (e) => e.preventDefault(), {
       once: true,
     });
     assert_false(invokee.muted);
-    invokerbutton.setAttribute("invokeaction", "toggleMuted");
+    invokerbutton.setAttribute("command", "toggleMuted");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
@@ -236,14 +218,14 @@
 
   promise_test(async function (t) {
     t.add_cleanup(async () => {
-      invokerbutton.removeAttribute("invokeaction");
+      invokerbutton.removeAttribute("command");
       invokee.pause();
       invokee.currentTime = 0;
       invokee.muted = false;
     });
     invokee.muted = true;
     assert_true(invokee.muted);
-    invokerbutton.setAttribute("invokeaction", "toggleMuted");
+    invokerbutton.setAttribute("command", "toggleMuted");
     await clickOn(invokerbutton);
     await new Promise((resolve) => {
       requestAnimationFrame(resolve);
diff --git a/tests/wpt/tests/html/semantics/popovers/popover-attribute-basic.html b/tests/wpt/tests/html/semantics/popovers/popover-attribute-basic.html
index 2af3bbc137f..f13a05288c3 100644
--- a/tests/wpt/tests/html/semantics/popovers/popover-attribute-basic.html
+++ b/tests/wpt/tests/html/semantics/popovers/popover-attribute-basic.html
@@ -233,6 +233,31 @@ window.onload = () => {
     assert_false(popover.matches(':popover-open'),'popover is not shown if its type changed during show');
   },`Changing the popover type in a "beforetoggle" event handler should throw an exception (during showPopover())`);
 
+  test((t) => {
+    const other_popover = createPopover(t);
+    other_popover.setAttribute('popover','auto');
+    other_popover.showPopover();
+    const popover = createPopover(t);
+    popover.setAttribute('popover','auto');
+    other_popover.addEventListener('beforetoggle', (e) => {
+      if (e.newState !== "closed")
+        return;
+      popover.setAttribute('popover','manual');
+    },{once: true});
+    assert_true(other_popover.matches(':popover-open'));
+    assert_false(popover.matches(':popover-open'));
+
+    popover.id = 'type-change-test';
+    const invoker = document.createElement('button');
+    document.body.appendChild(invoker);
+    t.add_cleanup(() => invoker.remove());
+    invoker.setAttribute('popovertarget', 'type-change-test');
+    invoker.click();
+
+    assert_false(other_popover.matches(':popover-open'),'unrelated popover is hidden');
+    assert_false(popover.matches(':popover-open'),'popover is not shown if its type changed during show');
+  },`Changing the popover type in a "beforetoggle" event handler should not show the popover (during popovertarget invoking)`);
+
   test((t) => {
     const popover = createPopover(t);
     popover.setAttribute('popover','auto');
diff --git a/tests/wpt/tests/interfaces/invokers.tentative.idl b/tests/wpt/tests/interfaces/invokers.tentative.idl
index eb1b8247f06..4724d7deb08 100644
--- a/tests/wpt/tests/interfaces/invokers.tentative.idl
+++ b/tests/wpt/tests/interfaces/invokers.tentative.idl
@@ -1,15 +1,15 @@
 interface mixin InvokerElement {
-  [CEReactions,Reflect=invoketarget] attribute Element? invokeTargetElement;
-  [CEReactions,Reflect=invokeaction] attribute DOMString invokeAction;
+  [CEReactions,Reflect=invoketarget] attribute Element? commandForElement;
+  [CEReactions,Reflect=invokeaction] attribute DOMString command;
 };
 
-interface InvokeEvent : Event {
-    constructor(DOMString type, optional InvokeEventInit eventInitDict = {});
+interface CommandEvent : Event {
+    constructor(DOMString type, optional CommandEventInit eventInitDict = {});
     readonly attribute Element? invoker;
-    readonly attribute DOMString action;
+    readonly attribute DOMString command;
 };
 
-dictionary InvokeEventInit : EventInit {
+dictionary CommandEventInit : EventInit {
     Element? invoker = null;
-    DOMString action = "";
+    DOMString command = "";
 };
diff --git a/tests/wpt/tests/intersection-observer/v2/box-reflect.html b/tests/wpt/tests/intersection-observer/v2/box-reflect.html
new file mode 100644
index 00000000000..41e072a587c
--- /dev/null
+++ b/tests/wpt/tests/intersection-observer/v2/box-reflect.html
@@ -0,0 +1,50 @@
+<!DOCTYPE html>
+<meta name="viewport" content="width=device-width,initial-scale=1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../resources/intersection-observer-test-utils.js"></script>
+
+<style>
+body, html {
+  margin: 0;
+}
+pre, #log {
+  position: absolute;
+  top: 0;
+  left: 200px;
+}
+#reflect {
+  width: 100px;
+  height: 100px;
+  background-color: hotpink;
+  -webkit-box-reflect: below 10px;
+  margin: 10px 0;
+}
+</style>
+
+<div id="reflect"></div>
+<div id="target">Hello, world!</div>
+
+<script>
+var delay = 100;
+var entries = [];
+var target;
+var supported = CSS.supports("-webkit-box-reflect", "below 10px");
+
+runTestCycle(function() {
+  target = document.getElementById("target");
+  assert_true(!!target, "target exists");
+  let observer = new IntersectionObserver(function(changes) {
+    entries = entries.concat(changes)
+  }, {trackVisibility: true, delay: delay});
+  observer.observe(target);
+  entries = entries.concat(observer.takeRecords());
+  assert_equals(entries.length, 0, "No initial notifications.");
+  runTestCycle(step0, "First rAF.", delay);
+}, "IntersectionObserverV2 detects occlusion from -webkit-box-reflect (if supported).", delay);
+
+function step0() {
+  assert_equals(entries.length, 1, "Initial notification.");
+  assert_equals(entries[0].isVisible, !supported, "Occluded if -webkit-box-reflect is supported.");
+}
+</script>
diff --git a/tests/wpt/tests/lint.ignore b/tests/wpt/tests/lint.ignore
index 170f4136d4b..ca22175f33c 100644
--- a/tests/wpt/tests/lint.ignore
+++ b/tests/wpt/tests/lint.ignore
@@ -162,6 +162,8 @@ SET TIMEOUT: custom-elements/scoped-registry/scoped-registry-define-upgrade-crit
 SET TIMEOUT: encrypted-media/polyfill/chrome-polyfill.js
 SET TIMEOUT: encrypted-media/polyfill/clearkey-polyfill.js
 SET TIMEOUT: encrypted-media/scripts/playback-temporary-events.js
+SET TIMEOUT: fedcm/support/fedcm-iframe.html
+SET TIMEOUT: fedcm/support/fedcm/disconnect-iframe.html
 SET TIMEOUT: fetch/fetch-later/resources/fetch-later-helper.js
 SET TIMEOUT: fetch/metadata/resources/helper.sub.js
 SET TIMEOUT: fetch/metadata/resources/message-opener.html
@@ -294,8 +296,6 @@ SET TIMEOUT: workers/*
 SET TIMEOUT: xhr/resources/init.htm
 SET TIMEOUT: xhr/resources/xmlhttprequest-timeout.js
 SET TIMEOUT: fenced-frame/resolve-to-config-promise.https.html
-SET TIMEOUT: credential-management/support/fedcm-iframe.html
-SET TIMEOUT: credential-management/support/fedcm/disconnect-iframe.html
 
 # generate_tests implementation and sample usage
 GENERATE_TESTS: resources/test/tests/functional/generate-callback.html
@@ -405,7 +405,7 @@ SET TIMEOUT: speculation-rules/prerender/resources/media-autoplay-attribute.html
 SET TIMEOUT: speculation-rules/prerender/resources/media-play.html
 SET TIMEOUT: html/browsers/browsing-the-web/back-forward-cache/timers.html
 SET TIMEOUT: dom/abort/crashtests/timeout-close.html
-SET TIMEOUT: storage-access-api/storage-access-beyond-cookies.locks.tentative.sub.https.window.js
+SET TIMEOUT: storage-access-api/storage-access-beyond-cookies.locks.sub.https.window.js
 
 # setTimeout use in reftests
 SET TIMEOUT: acid/acid3/test.html
@@ -608,7 +608,7 @@ WEB-PLATFORM.TEST:web-bundle/subresource-loading/resources/*.js
 # https://github.com/web-platform-tests/wpt/issues/16455
 # Please consult with ecosystem-infra@chromium.org before adding more.
 MISSING DEPENDENCY: credential-management/support/otpcredential-helper.js
-MISSING DEPENDENCY: credential-management/support/fedcm-mock.js
+MISSING DEPENDENCY: fedcm/support/fedcm-mock.js
 MISSING DEPENDENCY: resources/chromium/content-index-helpers.js
 MISSING DEPENDENCY: resources/chromium/contacts_manager_mock.js
 MISSING DEPENDENCY: resources/chromium/web-bluetooth-test.js
diff --git a/tests/wpt/tests/long-animation-frame/tentative/loaf-pointer-without-render-iframe.html b/tests/wpt/tests/long-animation-frame/tentative/loaf-pointer-without-render-iframe.html
new file mode 100644
index 00000000000..1fb106403a1
--- /dev/null
+++ b/tests/wpt/tests/long-animation-frame/tentative/loaf-pointer-without-render-iframe.html
@@ -0,0 +1,57 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>Long Animation Frame Timing: Pointer events without render in an iframe</title>
+<meta name="timeout" content="long">
+<script src=/resources/testdriver.js></script>
+<script src=/resources/testdriver-actions.js></script>
+<script src=/resources/testdriver-vendor.js></script>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/utils.js"></script>
+<body>
+<script>
+const BUSY_DURATION = 60;
+function event_handler() {
+  busy_wait(BUSY_DURATION);
+}
+
+function click_iframe(iframe) {
+  return new test_driver.Actions()
+    .pointerMove(10, 10, {origin: iframe})
+    .pointerDown()
+    .pointerUp()
+    .send();
+}
+
+promise_test(async t => {
+  const iframe = document.createElement("iframe");
+  iframe.src = "resources/long-pointerdown.html"
+  t.add_cleanup(() => iframe.remove());
+  document.body.append(iframe);
+  await new Promise(resolve => iframe.addEventListener("load", resolve));
+  iframe.focus();
+  await click_iframe(iframe);
+  await new Promise(resolve => requestAnimationFrame(() => resolve()));
+  await new Promise(resolve => t.step_timeout(resolve, 0));
+  const loaf_promise = new Promise(resolve => {
+    function on_message(event) {
+      resolve(event.data);
+    }
+
+    addEventListener("message", on_message);
+    t.add_cleanup(() => removeEventListener("message", on_message));
+
+    new PerformanceObserver(entries => {
+      for (const e of entries.getEntries())
+        if (entries.getEntries().some(
+          e => !e.renderStart && e.scripts.some(script => script.invoker === "BODY.onpointerdown")))
+          resolve("MAIN");
+      }).observe({type: "long-animation-frame"});
+    });
+
+    await click_iframe(iframe);
+
+  assert_equals(await loaf_promise, "FRAME");
+}, "Input events in iframes that don't cause a render should only create LoAF for the iframe")
+</script>
+</body>
diff --git a/tests/wpt/tests/long-animation-frame/tentative/loaf-pointer-without-render.html b/tests/wpt/tests/long-animation-frame/tentative/loaf-pointer-without-render.html
new file mode 100644
index 00000000000..f05cb218ba6
--- /dev/null
+++ b/tests/wpt/tests/long-animation-frame/tentative/loaf-pointer-without-render.html
@@ -0,0 +1,38 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>Long Animation Frame Timing: Pointer event without render in the main frame</title>
+<meta name="timeout" content="long">
+<script src=/resources/testdriver.js></script>
+<script src=/resources/testdriver-actions.js></script>
+<script src=/resources/testdriver-vendor.js></script>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/utils.js"></script>
+<style>
+  * {
+    user-select: none;
+  }
+</style>
+<body>
+<h1>Test</h1>
+<script>
+promise_test(async t => {
+  document.body.addEventListener("pointerdown", () => {
+    busy_wait(60);
+  });
+  const loaf_promise = new Promise(resolve => new PerformanceObserver(entries => {
+      if (entries.getEntries().some(
+        e => e.scripts.some(script => script.invoker === "BODY.onpointerdown"))) {
+          resolve("OK");
+        }
+  }).observe({type: "long-animation-frame"}));
+
+  const actions = new test_driver.Actions();
+  await actions.pointerMove(10, 10, {origin: document.body})
+  .pointerDown()
+    .pointerUp()
+    .send();
+  assert_equals(await loaf_promise, "OK");
+}, "Input events should create a LoAF even if they don't generate a frame")
+</script>
+</body>
diff --git a/tests/wpt/tests/long-animation-frame/tentative/resources/long-pointerdown.html b/tests/wpt/tests/long-animation-frame/tentative/resources/long-pointerdown.html
new file mode 100644
index 00000000000..34e8115086c
--- /dev/null
+++ b/tests/wpt/tests/long-animation-frame/tentative/resources/long-pointerdown.html
@@ -0,0 +1,26 @@
+<!DOCTYPE html>
+<head>
+    <script src="utils.js"></script>
+    <style>
+        body {
+            width: 200px;
+            height: 200px;
+        }
+
+        * {
+            user-select: none;
+        }
+    </style>
+<body>
+    <script>
+        document.body.addEventListener("pointerdown", () => {
+            busy_wait(120)
+        });
+        new PerformanceObserver(entries => {
+            if (entries.getEntries().some(
+                e => e.scripts.some(script => script.invoker === "BODY.onpointerdown"))) {
+                window.parent.postMessage("FRAME", "*");
+            }
+        }).observe({type: "long-animation-frame"});
+    </script>
+</body>
diff --git a/tests/wpt/tests/long-animation-frame/tentative/resources/utils.js b/tests/wpt/tests/long-animation-frame/tentative/resources/utils.js
index aa537d39a78..b51ab891dcd 100644
--- a/tests/wpt/tests/long-animation-frame/tentative/resources/utils.js
+++ b/tests/wpt/tests/long-animation-frame/tentative/resources/utils.js
@@ -1,7 +1,9 @@
 const windowLoaded = new Promise(resolve => window.addEventListener('load', resolve));
-setup(() =>
-  assert_implements(window.PerformanceLongAnimationFrameTiming,
-    'Long animation frames are not supported.'));
+if ("setup" in globalThis) {
+  setup(() =>
+    assert_implements(window.PerformanceLongAnimationFrameTiming,
+      'Long animation frames are not supported.'));
+}
 
 const very_long_frame_duration = 360;
 const no_long_frame_timeout = very_long_frame_duration * 2;
diff --git a/tests/wpt/tests/mathml/presentation-markup/mrow/mrow-fallback.html b/tests/wpt/tests/mathml/presentation-markup/mrow/mrow-fallback.html
index 3f9d466148c..a7e984328c5 100644
--- a/tests/wpt/tests/mathml/presentation-markup/mrow/mrow-fallback.html
+++ b/tests/wpt/tests/mathml/presentation-markup/mrow/mrow-fallback.html
@@ -11,6 +11,10 @@
 <script src="/mathml/support/fonts.js"></script>
 <script src="/mathml/support/layout-comparison.js"></script>
 <script src="/mathml/support/mathml-fragments.js"></script>
+<style>
+  /* Revert style specified in the UA style sheet that changes box size. */
+  mfrac { padding-inline: 0; }
+</style>
 <script>
   setup({ explicit_done: true });
   window.addEventListener("load", () => { loadAllFonts().then(runTests); });
diff --git a/tests/wpt/tests/mathml/relations/css-styling/padding-border-margin/padding-border-margin-004-ref.html b/tests/wpt/tests/mathml/relations/css-styling/padding-border-margin/padding-border-margin-004-ref.html
new file mode 100644
index 00000000000..4da9af7ffc3
--- /dev/null
+++ b/tests/wpt/tests/mathml/relations/css-styling/padding-border-margin/padding-border-margin-004-ref.html
@@ -0,0 +1,26 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8"/>
+<title>Padding/border/margin on an mi with italic mathvariant (reference)</title>
+<style>
+  @font-face {
+    font-family: TestFont;
+    src: url("/fonts/math/mathvariant-italic.woff");
+  }
+  math  {
+    font-family: TestFont;
+    font-size: 300px;
+  }
+</style>
+<body>
+  <p>This test passes if you see the text <code>1d434</code> in cyan on a blue
+    background, surrounded by a 10px padding, surrounded by a 10px
+    yellow dashed border, itself surrounded by a 10px pink margin.</p>
+  <div style="background: pink; position: absolute; left: 10px; top: 4em;">
+    <math>
+      <mtext style="background: blue; border: 10px dashed yellow; padding: 10px; margin: 10px; color: cyan;">&#x1D434;</mtext>
+    </math>
+  </div>
+</body>
+</html>
diff --git a/tests/wpt/tests/mathml/relations/css-styling/padding-border-margin/padding-border-margin-004.html b/tests/wpt/tests/mathml/relations/css-styling/padding-border-margin/padding-border-margin-004.html
new file mode 100644
index 00000000000..ee8196d8597
--- /dev/null
+++ b/tests/wpt/tests/mathml/relations/css-styling/padding-border-margin/padding-border-margin-004.html
@@ -0,0 +1,33 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8"/>
+<title>Padding/border/margin on an mi with italic mathvariant</title>
+<link rel="help" href="https://w3c.github.io/mathml-core/#layout-algorithms">
+<link rel="help" href="https://w3c.github.io/mathml-core/#css-styling">
+<link rel="help" href="https://w3c.github.io/mathml-core/#the-mathvariant-attribute">
+<link rel="help" href="https://w3c.github.io/mathml-core/#new-text-transform-values">
+<link rel="help" href="https://w3c.github.io/mathml-core/#italic-mappings">
+<link rel="match" href="padding-border-margin-004-ref.html"/>
+<meta name="assert" content="Verify visual rendering of padding/border/margin on an mi with italic mathvariant.">
+<style>
+  @font-face {
+    font-family: TestFont;
+    src: url("/fonts/math/mathvariant-italic.woff");
+  }
+  math  {
+    font-family: TestFont;
+    font-size: 300px;
+  }
+</style>
+<body>
+  <p>This test passes if you see the text <code>1d434</code> in cyan on a blue
+    background, surrounded by a 10px padding, surrounded by a 10px
+    yellow dashed border, itself surrounded by a 10px pink margin.</p>
+  <div style="background: pink; position: absolute; left: 10px; top: 4em;">
+    <math>
+      <mi style="background: blue; border: 10px dashed yellow; padding: 10px; margin: 10px; color: cyan;">&#x41;</mi>
+    </math>
+  </div>
+</body>
+</html>
diff --git a/tests/wpt/tests/permissions-policy/payment-allowed-by-permissions-policy-attribute-redirect-on-load.https.sub.html b/tests/wpt/tests/permissions-policy/payment-allowed-by-permissions-policy-attribute-redirect-on-load.https.sub.html
index b95deed7cef..57ae4fbee45 100644
--- a/tests/wpt/tests/permissions-policy/payment-allowed-by-permissions-policy-attribute-redirect-on-load.https.sub.html
+++ b/tests/wpt/tests/permissions-policy/payment-allowed-by-permissions-policy-attribute-redirect-on-load.https.sub.html
@@ -3,12 +3,13 @@
   <script src=/resources/testharness.js></script>
   <script src=/resources/testharnessreport.js></script>
   <script src=/permissions-policy/resources/permissions-policy.js></script>
+  <script src=/common/get-host-info.sub.js></script>
   <script>
   'use strict';
   var relative_path = '/permissions-policy/resources/permissions-policy-payment.html';
   var base_src = '/permissions-policy/resources/redirect-on-load.html#';
   var same_origin_src = base_src + relative_path;
-  var cross_origin_src = base_src + 'https://{{domains[www]}}:{{ports[https][0]}}' +
+  var cross_origin_src = base_src + get_host_info().REMOTE_ORIGIN +
     relative_path;
   var header = 'permissions policy allow="payment"';
 
diff --git a/tests/wpt/tests/resources/chromium/web-bluetooth-test.js b/tests/wpt/tests/resources/chromium/web-bluetooth-test.js
index ecea5e760c6..67c3c4ee1b4 100644
--- a/tests/wpt/tests/resources/chromium/web-bluetooth-test.js
+++ b/tests/wpt/tests/resources/chromium/web-bluetooth-test.js
@@ -603,7 +603,7 @@ async function initializeChromiumResources() {
   content.mojom = await import(
       '/gen/content/web_test/common/fake_bluetooth_chooser.mojom.m.js');
   bluetooth.mojom = await import(
-      '/gen/device/bluetooth/public/mojom/test/fake_bluetooth.mojom.m.js');
+      '/gen/device/bluetooth/public/mojom/emulation/fake_bluetooth.mojom.m.js');
 
   const map = MOJO_CHOOSER_EVENT_TYPE_MAP;
   const types = content.mojom.ChooserEventType;
diff --git a/tests/wpt/tests/sanitizer-api/sanitizer-names.https.html b/tests/wpt/tests/sanitizer-api/sanitizer-names.https.html
index cd33bbc7635..78f1d605a19 100644
--- a/tests/wpt/tests/sanitizer-api/sanitizer-names.https.html
+++ b/tests/wpt/tests/sanitizer-api/sanitizer-names.https.html
@@ -140,7 +140,7 @@
     test(t => {
       const elems = ["svg:" + elem];
       assert_array_equals(
-        new Sanitizer({elements: elems}).getConfiguration().allowElements,
+        new Sanitizer({elements: elems}).getConfiguration().allowElements.toSorted(),
         elems);
     }, `Mixed case element names #${index}: "${elem}" is preserved in config.`);
   });
diff --git a/tests/wpt/tests/selection/caret/after-designMode-off-ref.html b/tests/wpt/tests/selection/caret/after-designMode-off-ref.html
new file mode 100644
index 00000000000..fbb3c2467e8
--- /dev/null
+++ b/tests/wpt/tests/selection/caret/after-designMode-off-ref.html
@@ -0,0 +1,11 @@
+<!doctype html>
+<html>
+<head>
+<meta charset="utf-8">
+<meta name="viewport" content="width=device-width,initial-scale=1">
+<style>
+* { color: green; }
+</style>
+</head>
+<body>&lt;-- No caret should appear here.</body>
+</html>
diff --git a/tests/wpt/tests/selection/caret/after-designMode-off.html b/tests/wpt/tests/selection/caret/after-designMode-off.html
new file mode 100644
index 00000000000..c5ccd66cc4b
--- /dev/null
+++ b/tests/wpt/tests/selection/caret/after-designMode-off.html
@@ -0,0 +1,25 @@
+<!doctype html>
+<html class="reftest-wait">
+<head>
+<meta charset="utf-8">
+<meta name="viewport" content="width=device-width,initial-scale=1">
+<link rel="match" href="after-designMode-off-ref.html">
+<style>
+:read-only { color: green; }
+:read-write { color: red; }
+</style>
+<script>
+addEventListener("load", () => {
+  requestAnimationFrame(()=> {
+    document.designMode='on';
+    getSelection().collapse(document.body.firstChild, 0);
+    requestAnimationFrame(()=> {
+        document.designMode='off';
+        document.documentElement.removeAttribute("class");
+    });
+  });
+}, {once: true});
+</script>
+</head>
+<body>&lt;-- No caret should appear here.</body>
+</html>
diff --git a/tests/wpt/tests/selection/onselectionchange-on-document.html b/tests/wpt/tests/selection/onselectionchange-on-document.html
index 4e061653777..af522c3f79c 100644
--- a/tests/wpt/tests/selection/onselectionchange-on-document.html
+++ b/tests/wpt/tests/selection/onselectionchange-on-document.html
@@ -11,7 +11,7 @@ promise_test(() => {
   return new Promise(resolve => {
     let didFireSelectionChangeEvent = false;
     document.addEventListener("selectionchange", () => { didFireSelectionChangeEvent = true; resolve(); }, {once: true});
-    getSelection().setPosition(container, 0);
+    getSelection().setPosition(container, 1);
     assert_false(didFireSelectionChangeEvent);
   });
 }, "selectionchange event on document fires");
@@ -21,7 +21,7 @@ promise_test(() => {
     let selectionChangeCount = 0;
     document.addEventListener("selectionchange", () => ++selectionChangeCount);
     container.innerHTML = '<span><br></span><span><br></span>';
-    getSelection().setPosition(container, 0);
+    getSelection().setPosition(container, 1);
     assert_equals(selectionChangeCount, 0);
     getSelection().setPosition(container, 2);
     assert_equals(selectionChangeCount, 0);
@@ -35,7 +35,7 @@ promise_test(() => {
     let selectionChangeCount = 0;
     document.addEventListener("selectionchange", () => ++selectionChangeCount);
     container.innerHTML = '<span><br></span><span><br></span>';
-    getSelection().setPosition(container, 0);
+    getSelection().setPosition(container, 1);
     assert_equals(selectionChangeCount, 0);
     getSelection().setPosition(container, 2);
     assert_equals(selectionChangeCount, 0);
@@ -61,7 +61,7 @@ promise_test(() => {
       ++selectionChangeCount;
     });
     container.innerHTML = '<b><br></b><b><br></b>';
-    getSelection().setPosition(container, 0);
+    getSelection().setPosition(container, 1);
     assert_equals(selectionChangeCount, 0);
     await new Promise(setTimeout);
     assert_equals(selectionChangeCount, 1);
diff --git a/tests/wpt/tests/shadow-dom/selection-direction.tentative.html b/tests/wpt/tests/shadow-dom/selection-direction.tentative.html
index 6ec9b1934f9..340711a8f06 100644
--- a/tests/wpt/tests/shadow-dom/selection-direction.tentative.html
+++ b/tests/wpt/tests/shadow-dom/selection-direction.tentative.html
@@ -3,7 +3,7 @@
 <body>
 <meta name="author" title="Ryosuke Niwa" href="mailto:rniwa@webkit.org">
 <meta name="assert" content="Selection's direction should return none, forwad, or backward">
-<link rel="help" href="https://w3c.github.io/selection-api/#dom-selection-getcomposedrange">
+<link rel="help" href="https://w3c.github.io/selection-api/#dom-selection-direction">
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
 <script src="/resources/testdriver.js"></script>
@@ -61,63 +61,6 @@ test(() => {
     assert_equals(getSelection().direction, 'backward');
 }, 'direction returns "backward" when there is a forward selection that crosses shadow boundaries');
 
-promise_test(async () => {
-    container.innerHTML = 'hello, world';
-    const doubleClick = new test_driver.Actions()
-      .pointerMove(0, 0, container.firstChild)
-      .pointerDown()
-      .pointerUp()
-      .pointerDown()
-      .pointerUp()
-      .send();
-    await doubleClick;
-
-    const sel = getSelection();
-    assert_equals(sel.anchorNode, container.firstChild);
-    assert_equals(sel.anchorOffset, 0);
-    assert_equals(sel.focusNode, container.firstChild);
-    assert_equals(sel.focusOffset, 5); // hello
-    assert_equals(sel.direction, 'none');
-}, 'direction returns "none" when there is a double click selection(directionless)');
-
-promise_test(async () => {
-    container.innerHTML = 'hello, world';
-    const tripleClick = new test_driver.Actions()
-      .pointerMove(0, 0, container.firstChild)
-      .pointerDown()
-      .pointerUp()
-      .pointerDown()
-      .pointerUp()
-      .pointerDown()
-      .pointerUp()
-      .send();
-    await tripleClick;
-
-    const sel = getSelection();
-    assert_equals(sel.anchorNode, container);
-    assert_equals(sel.anchorOffset, 0);
-    assert_equals(sel.focusNode, container);
-    assert_equals(sel.focusOffset, 1);
-    assert_equals(sel.direction, 'none');
-}, 'direction returns "none" when there is a triple click selection(directionless)');
-
-promise_test(async () => {
-    container.innerHTML = 'hello, world';
-    const click = new test_driver.Actions()
-      .pointerMove(0, 0, container.firstChild)
-      .pointerDown()
-      .pointerUp()
-      .send();
-    await click;
-
-    const sel = getSelection();
-    assert_equals(sel.anchorNode, container.firstChild);
-    assert_equals(sel.anchorOffset, 0);
-    assert_equals(sel.focusNode, container.firstChild);
-    assert_equals(sel.focusOffset, 0);
-    assert_true(sel.isCollapsed);
-    assert_equals(sel.direction, 'none');
-}, 'direction returns "none" when the selection is collapsed');
 </script>
 </body>
 </html>
diff --git a/tests/wpt/tests/storage-access-api/resources/storage-access-beyond-cookies-iframe-iframe.html b/tests/wpt/tests/storage-access-api/resources/storage-access-beyond-cookies-iframe-iframe.html
index cfc7d599a1b..44ac9cd8986 100644
--- a/tests/wpt/tests/storage-access-api/resources/storage-access-beyond-cookies-iframe-iframe.html
+++ b/tests/wpt/tests/storage-access-api/resources/storage-access-beyond-cookies-iframe-iframe.html
@@ -9,7 +9,7 @@
   const type = (new URLSearchParams(window.location.search)).get("type");
   const id = (new URLSearchParams(window.location.search)).get("id");
   let message = "HasAccess for " + type;
-  // Step 6 (storage-access-api/storage-access-beyond-cookies.{}.tentative.sub.https.html)
+  // Step 6 (storage-access-api/storage-access-beyond-cookies.{}.sub.https.html)
   try {
     await MaybeSetStorageAccess("*", "*", "blocked");
     await test_driver.set_permission({ name: 'storage-access' }, 'granted');
@@ -334,7 +334,7 @@
   } catch (_) {
     message = "Unable to load handle in same-origin context for " + type;
   }
-  // Step 7 (storage-access-api/storage-access-beyond-cookies.{}.tentative.sub.https.html)
+  // Step 7 (storage-access-api/storage-access-beyond-cookies.{}.sub.https.html)
   await MaybeSetStorageAccess("*", "*", "allowed");
   await test_driver.set_permission({ name: 'storage-access' }, 'prompt');
   window.top.postMessage({type: "result", message: message}, "*");
diff --git a/tests/wpt/tests/storage-access-api/resources/storage-access-beyond-cookies-iframe.sub.html b/tests/wpt/tests/storage-access-api/resources/storage-access-beyond-cookies-iframe.sub.html
index 3d9f5bb1ef2..7d43a06bc7e 100644
--- a/tests/wpt/tests/storage-access-api/resources/storage-access-beyond-cookies-iframe.sub.html
+++ b/tests/wpt/tests/storage-access-api/resources/storage-access-beyond-cookies-iframe.sub.html
@@ -13,7 +13,7 @@ window.addEventListener("message", async (e) => {
   const type = (new URLSearchParams(window.location.search)).get("type");
   const id = (new URLSearchParams(window.location.search)).get("id");
   let message = "";
-  // Step 4 (storage-access-api/storage-access-beyond-cookies.{}.tentative.sub.https.html)
+  // Step 4 (storage-access-api/storage-access-beyond-cookies.{}.sub.https.html)
   try {
     await MaybeSetStorageAccess("*", "*", "blocked");
     if (type == "cookies") {
@@ -153,7 +153,7 @@ window.addEventListener("message", async (e) => {
     window.top.postMessage({type: "result", message: message}, "*");
     return;
   }
-  // Step 5 (storage-access-api/storage-access-beyond-cookies.{}.tentative.sub.https.html)
+  // Step 5 (storage-access-api/storage-access-beyond-cookies.{}.sub.https.html)
   let iframe = document.createElement("iframe");
   iframe.src = "https://{{hosts[][]}}:{{ports[https][0]}}/storage-access-api/resources/storage-access-beyond-cookies-iframe-iframe.html?type=" + type + "&id=" + id;
   document.body.appendChild(iframe);
diff --git a/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.BroadcastChannel.tentative.sub.https.window.js b/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.BroadcastChannel.sub.https.window.js
similarity index 100%
rename from tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.BroadcastChannel.tentative.sub.https.window.js
rename to tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.BroadcastChannel.sub.https.window.js
diff --git a/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.SharedWorker.tentative.sub.https.window.js b/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.SharedWorker.sub.https.window.js
similarity index 97%
rename from tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.SharedWorker.tentative.sub.https.window.js
rename to tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.SharedWorker.sub.https.window.js
index 613a47ba1b7..e05c2ef38d1 100644
--- a/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.SharedWorker.tentative.sub.https.window.js
+++ b/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.SharedWorker.sub.https.window.js
@@ -12,7 +12,6 @@
 // Step 6 (sub-sub-frame) Try to use storage access API to access first-party shared worker.
 // Step 7 (sub-sub-frame) Send "HasAccess for SharedWorker" message to top-frame.
 // Step 8 (top-frame) Set up cookie worker to expect it's already opened.
-// TODO(crbug.com/1484966): Verify access to cookies in shared workers.
 
 async_test(t => {
   // Step 1
diff --git a/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.blobStorage.tentative.sub.https.window.js b/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.blobStorage.sub.https.window.js
similarity index 100%
rename from tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.blobStorage.tentative.sub.https.window.js
rename to tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.blobStorage.sub.https.window.js
diff --git a/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.caches.tentative.sub.https.window.js b/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.caches.sub.https.window.js
similarity index 100%
rename from tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.caches.tentative.sub.https.window.js
rename to tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.caches.sub.https.window.js
diff --git a/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.cookies.tentative.sub.https.window.js b/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.cookies.sub.https.window.js
similarity index 100%
rename from tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.cookies.tentative.sub.https.window.js
rename to tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.cookies.sub.https.window.js
diff --git a/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.estimate.tentative.sub.https.window.js b/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.estimate.sub.https.window.js
similarity index 100%
rename from tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.estimate.tentative.sub.https.window.js
rename to tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.estimate.sub.https.window.js
diff --git a/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.getDirectory.tentative.sub.https.window.js b/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.getDirectory.sub.https.window.js
similarity index 100%
rename from tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.getDirectory.tentative.sub.https.window.js
rename to tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.getDirectory.sub.https.window.js
diff --git a/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.indexedDB.tentative.sub.https.window.js b/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.indexedDB.sub.https.window.js
similarity index 100%
rename from tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.indexedDB.tentative.sub.https.window.js
rename to tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.indexedDB.sub.https.window.js
diff --git a/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.localStorage.tentative.sub.https.window.js b/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.localStorage.sub.https.window.js
similarity index 100%
rename from tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.localStorage.tentative.sub.https.window.js
rename to tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.localStorage.sub.https.window.js
diff --git a/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.locks.tentative.sub.https.window.js b/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.locks.sub.https.window.js
similarity index 100%
rename from tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.locks.tentative.sub.https.window.js
rename to tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.locks.sub.https.window.js
diff --git a/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.none.tentative.sub.https.window.js b/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.none.sub.https.window.js
similarity index 100%
rename from tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.none.tentative.sub.https.window.js
rename to tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.none.sub.https.window.js
diff --git a/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.sessionStorage.tentative.sub.https.window.js b/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.sessionStorage.sub.https.window.js
similarity index 100%
rename from tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.sessionStorage.tentative.sub.https.window.js
rename to tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.sessionStorage.sub.https.window.js
diff --git a/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.unpartitioned.tentative.sub.https.window.js b/tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.unpartitioned.sub.https.window.js
similarity index 100%
rename from tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.unpartitioned.tentative.sub.https.window.js
rename to tests/wpt/tests/storage-access-api/storage-access-beyond-cookies.unpartitioned.sub.https.window.js
diff --git a/tests/wpt/tests/svg/painting/reftests/non-scaling-stroke-003.html b/tests/wpt/tests/svg/painting/reftests/non-scaling-stroke-003.html
index 147bf814d30..4fec5711d6c 100644
--- a/tests/wpt/tests/svg/painting/reftests/non-scaling-stroke-003.html
+++ b/tests/wpt/tests/svg/painting/reftests/non-scaling-stroke-003.html
@@ -1,6 +1,6 @@
 <!DOCTYPE html>
 <html>
-<title>non-scaling-stroke with screen transform</title>
+<title>non-scaling-stroke with outer viewport transform</title>
 <link rel="help" href="https://svgwg.org/svg2-draft/painting.html#PaintingVectorEffects" />
 <link rel="match" href="green-100x100.svg" />
 <body>
@@ -10,24 +10,30 @@
       margin: 0;
       width: 200px;
       height: 200px;
-      transform: scale(0.5);
     }
     svg {
-      width: 100px;
-      height: 100px;
-      transform: scale(2) translate(-25px, -25px);
       transform-origin: center;
       transform-bxox: fill-box;
     }
+    #outer {
+      width: 100px;
+      height: 100px;
+      transform: scale(2);
+    }
+    #inner {
+      transform: scale(0.5);
+    }
     rect {
       fill: red;
       stroke: green;
       stroke-width: 75px;
-      vector-effect: non-scaling-stroke screen;
+      vector-effect: non-scaling-stroke;
     }
   </style>
-  <svg>
-    <rect width="75" height="75"/>
+  <svg id="outer">
+    <svg id="inner">
+      <rect width="75" height="75"/>
+    </svg>
   </svg>
 </body>
 </html>
diff --git a/tests/wpt/tests/svg/painting/reftests/symbol-in-mask.html b/tests/wpt/tests/svg/painting/reftests/symbol-in-mask.html
new file mode 100644
index 00000000000..da1e11f1704
--- /dev/null
+++ b/tests/wpt/tests/svg/painting/reftests/symbol-in-mask.html
@@ -0,0 +1,31 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <title>Mask behaviour when mask contains a symbol element</title>
+  <link rel="match" href="green-100x100.svg">
+  <link rel="help" href="https://drafts.fxtf.org/css-masking-1/#MaskElement">
+  <meta name="assert" content="A symbol in a mask should not be displayed">
+</head>
+<style>
+  html, body, svg {
+    padding: 0;
+    margin: 0;
+  }
+</style>
+<body>
+  <svg width="200" height="200">
+    <defs>
+      <mask id="aMask">
+        <symbol>
+          <rect x="0" y="0" width="100" height="100" fill="#ffffff"/>
+        </symbol>
+      </mask>
+    </defs>
+    <rect width="100" height="100" fill="green"/>
+    <foreignObject width="200" height="200" style="mask: url('#aMask');">
+      <div style="width: 200px; height: 200px; background: red;"></div>
+    </foreignObject>
+  </svg>
+</body>
+</html>
diff --git a/tests/wpt/tests/svg/styling/vector-effect-invalid.html b/tests/wpt/tests/svg/styling/vector-effect-invalid.html
index ec49b88c599..18f82502ddd 100644
--- a/tests/wpt/tests/svg/styling/vector-effect-invalid.html
+++ b/tests/wpt/tests/svg/styling/vector-effect-invalid.html
@@ -18,6 +18,9 @@ test_invalid_value("vector-effect", "none screen");
 test_invalid_value("vector-effect", "viewport");
 test_invalid_value("vector-effect", "screen");
 test_invalid_value("vector-effect", "screen non-scaling-stroke");
+// The following were removed by https://github.com/w3c/svgwg/issues/582
+test_invalid_value("vector-effect", "non-scaling-stroke viewport");
+test_invalid_value("vector-effect", "non-scaling-stroke screen");
 </script>
 </body>
 </html>
diff --git a/tests/wpt/tests/svg/styling/vector-effect-valid.html b/tests/wpt/tests/svg/styling/vector-effect-valid.html
deleted file mode 100644
index 9563db0523b..00000000000
--- a/tests/wpt/tests/svg/styling/vector-effect-valid.html
+++ /dev/null
@@ -1,19 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-<meta charset="utf-8">
-<title>vector-effect test: parsing vector-effect with invalid values</title>
-<link rel="help" href="https://www.w3.org/TR/SVG2/coords.html#VectorEffects">
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<script src="/css/support/parsing-testcommon.js"></script>
-</head>
-<body>
-<script>
-test_valid_value("vector-effect", "none");
-test_valid_value("vector-effect", "non-scaling-stroke");
-test_valid_value("vector-effect", "non-scaling-stroke viewport", "non-scaling-stroke");
-test_valid_value("vector-effect", "non-scaling-stroke screen");
-</script>
-</body>
-</html>
diff --git a/tests/wpt/tests/tools/ci/requirements_tc.txt b/tests/wpt/tests/tools/ci/requirements_tc.txt
index a9128c02eb9..9bc3c840ab4 100644
--- a/tests/wpt/tests/tools/ci/requirements_tc.txt
+++ b/tests/wpt/tests/tools/ci/requirements_tc.txt
@@ -1,4 +1,4 @@
 pygithub==2.3.0
 pyyaml==6.0.1
 requests==2.32.3
-taskcluster==64.2.8
+taskcluster==66.0.0
diff --git a/tests/wpt/tests/tools/ci/tc/tasks/test.yml b/tests/wpt/tests/tools/ci/tc/tasks/test.yml
index a9ca07c6ceb..fffb146dacc 100644
--- a/tests/wpt/tests/tools/ci/tc/tasks/test.yml
+++ b/tests/wpt/tests/tools/ci/tc/tasks/test.yml
@@ -4,7 +4,7 @@ components:
     workerType: ci
     schedulerId: taskcluster-github
     deadline: "24 hours"
-    image: webplatformtests/wpt:0.57
+    image: ghcr.io/web-platform-tests/wpt:1
     maxRunTime: 7200
     artifacts:
       public/results:
diff --git a/tests/wpt/tests/tools/docker/README.md b/tests/wpt/tests/tools/docker/README.md
index bc98d198612..9ec7a99cfff 100644
--- a/tests/wpt/tests/tools/docker/README.md
+++ b/tests/wpt/tests/tools/docker/README.md
@@ -1,16 +1,17 @@
 This docker images is used for testing Chrome, Firefox, WebKitGTK and running
 other tasks on Taskcluster. When any of the files in this directory change, the
-images must be updated as well. Doing this requires you be part of the
-'webplatformtests' organization on Docker Hub; ping @foolip or @jpchase
-if you are not a member.
+images must be updated as well. Doing this requires you to have write
+permissions to the repository.
 
 The tag for a new docker image is of the form
-`webplatformtests/wpt:{current-version + 0.01}`
+`ghcr.io/web-platform-tests/wpt:${PREV_VERSION++}`.
 
 To update the docker image:
 
+* Run the workflow
+  https://github.com/web-platform-tests/wpt/actions/workflows/docker.yml via the
+  GitHub UI.
+
 * Update the following Taskcluster configurations to use the new image:
  - `.taskcluster.yml` (the decision task)
- - `tools/ci/tc/tasks/test.yml` (all the other tasks)
-
-* Run `wpt docker-push`
+ - `tools/ci/tc/tasks/test.yml` (all the other tasks)
\ No newline at end of file
diff --git a/tests/wpt/tests/tools/docker/frontend.py b/tests/wpt/tests/tools/docker/frontend.py
index f91e79fa78e..05f4e0fc8db 100644
--- a/tests/wpt/tests/tools/docker/frontend.py
+++ b/tests/wpt/tests/tools/docker/frontend.py
@@ -56,17 +56,10 @@ def read_image_name():
     return taskcluster_values, tests_value
 
 
-def lookup_tag(tag):
-    import requests
-    org, repo_version = tag.split("/", 1)
-    repo, version = repo_version.rsplit(":", 1)
-    resp = requests.get("https://hub.docker.com/v2/repositories/%s/%s/tags/%s" %
-                        (org, repo, version))
-    if resp.status_code == 200:
-        return True
-    if resp.status_code == 404:
-        return False
-    resp.raise_for_status()
+def tag_exists(tag):
+    retcode = subprocess.call(["docker", "manifest", "inspect", tag])
+    # The command succeeds if the tag exists.
+    return retcode != 0
 
 
 def push(venv, tag=None, force=False, *args, **kwargs):
@@ -89,13 +82,13 @@ def push(venv, tag=None, force=False, *args, **kwargs):
         logger.info("Using tag %s from .taskcluster.yml" % taskcluster_tag)
         tag = taskcluster_tag
 
-    tag_re = re.compile(r"webplatformtests/wpt:\d\.\d+")
+    tag_re = re.compile(r"ghcr.io/web-platform-tests/wpt:\d+")
     if not tag_re.match(tag):
-        error_log("Tag doesn't match expected format webplatformtests/wpt:0.x")
+        error_log("Tag doesn't match expected format ghcr.io/web-platform-tests/wpt:x")
         if not force:
             sys.exit(1)
 
-    if lookup_tag(tag):
+    if tag_exists(tag):
         # No override for this case
         logger.critical("Tag %s already exists" % tag)
         sys.exit(1)
diff --git a/tests/wpt/tests/tools/requirements_mypy.txt b/tests/wpt/tests/tools/requirements_mypy.txt
index 2addbba3b22..66ae1420387 100644
--- a/tests/wpt/tests/tools/requirements_mypy.txt
+++ b/tests/wpt/tests/tools/requirements_mypy.txt
@@ -1,4 +1,4 @@
-mypy==1.10.0
+mypy==1.10.1
 mypy-extensions==1.0.0
 toml==0.10.2
 tomli==2.0.1
diff --git a/tests/wpt/tests/tools/requirements_pytest.txt b/tests/wpt/tests/tools/requirements_pytest.txt
index 75d70d49bd8..14cc97014aa 100644
--- a/tests/wpt/tests/tools/requirements_pytest.txt
+++ b/tests/wpt/tests/tools/requirements_pytest.txt
@@ -1,3 +1,3 @@
 pytest==8.2.1
 pytest-cov==5.0.0
-hypothesis==6.100.2
+hypothesis==6.104.1
diff --git a/tests/wpt/tests/tools/requirements_tests.txt b/tests/wpt/tests/tools/requirements_tests.txt
index 74792e61314..c43af1ba8ba 100644
--- a/tests/wpt/tests/tools/requirements_tests.txt
+++ b/tests/wpt/tests/tools/requirements_tests.txt
@@ -2,5 +2,5 @@ httpx[http2]==0.27.0
 json-e==4.7.0
 jsonschema==4.17.3
 pyyaml==6.0.1
-taskcluster==64.2.8
+taskcluster==66.0.0
 mozterm==1.0.0
diff --git a/tests/wpt/tests/tools/webdriver/webdriver/bidi/client.py b/tests/wpt/tests/tools/webdriver/webdriver/bidi/client.py
index ee3ef1ea95d..d4cc78588e9 100644
--- a/tests/wpt/tests/tools/webdriver/webdriver/bidi/client.py
+++ b/tests/wpt/tests/tools/webdriver/webdriver/bidi/client.py
@@ -127,7 +127,7 @@ class BidiSession:
                   requested_capabilities: Optional[Mapping[str, Any]] = None) -> "BidiSession":
         """Create a BiDi session where there is no existing HTTP session
 
-        :param webdocket_url: URL to the WebSocket server listening for BiDi connections
+        :param websocket_url: URL to the WebSocket server listening for BiDi connections
         :param requested_capabilities: Capabilities request for establishing the session."""
         return cls(websocket_url, requested_capabilities=requested_capabilities)
 
diff --git a/tests/wpt/tests/tools/webdriver/webdriver/bidi/modules/network.py b/tests/wpt/tests/tools/webdriver/webdriver/bidi/modules/network.py
index 46c5885271a..dc895d9834c 100644
--- a/tests/wpt/tests/tools/webdriver/webdriver/bidi/modules/network.py
+++ b/tests/wpt/tests/tools/webdriver/webdriver/bidi/modules/network.py
@@ -1,3 +1,4 @@
+from enum import Enum
 from typing import Any, Dict, List, Mapping, MutableMapping, Optional, Union
 
 from ._module import BidiModule, command
@@ -8,6 +9,11 @@ class AuthCredentials(Dict[str, Any]):
         dict.__init__(self, type="password", username=username, password=password)
 
 
+class CacheBehavior(Enum):
+    BYPASS = "bypass"
+    DEFAULT = "default"
+
+
 class NetworkBase64Value(Dict[str, Any]):
     def __init__(self, value: str):
         dict.__init__(self, type="base64", value=value)
@@ -243,10 +249,11 @@ class Network(BidiModule):
         return params
 
     @command
-    def set_cache_bypass(
-        self, bypass: bool, contexts: Optional[List[str]] = None
-    ) -> Mapping[str, Any]:
-        params: MutableMapping[str, Any] = {"bypass": bypass}
+    def set_cache_behavior(
+            self,
+            cache_behavior: CacheBehavior,
+            contexts: Optional[List[str]] = None) -> Mapping[str, Any]:
+        params: MutableMapping[str, Any] = {"cacheBehavior": cache_behavior}
 
         if contexts is not None:
             params["contexts"] = contexts
diff --git a/tests/wpt/tests/tools/webdriver/webdriver/transport.py b/tests/wpt/tests/tools/webdriver/webdriver/transport.py
index ca1ff74ef96..7e898b2869f 100644
--- a/tests/wpt/tests/tools/webdriver/webdriver/transport.py
+++ b/tests/wpt/tests/tools/webdriver/webdriver/transport.py
@@ -224,15 +224,7 @@ class HTTPWireProtocol:
                 raise ValueError("Failed to encode request body as JSON:\n"
                                  "%s" % json.dumps(body, indent=2))
 
-        # When the timeout triggers, the TestRunnerManager thread will reuse
-        # this connection to check if the WebDriver its alive and we may end
-        # raising an httplib.CannotSendRequest exception if the WebDriver is
-        # not responding and this httplib.request() call is blocked on the
-        # runner thread. We use the boolean below to check for that and restart
-        # the connection in that case.
-        self._last_request_is_blocked = True
         response = self._request(method, uri, payload, headers, timeout=None)
-        self._last_request_is_blocked = False
         return Response.from_http(response, decoder=decoder, **codec_kwargs)
 
     def _request(self, method, uri, payload, headers=None, timeout=None):
@@ -248,6 +240,13 @@ class HTTPWireProtocol:
         if self._last_request_is_blocked or self._has_unread_data():
             self.close()
 
+        # When the timeout triggers, the TestRunnerManager thread will reuse
+        # this connection to check if the WebDriver its alive and we may end
+        # raising an httplib.CannotSendRequest exception if the WebDriver is
+        # not responding and this httplib.request() call is blocked on the
+        # runner thread. We use the boolean below to check for that and restart
+        # the connection in that case.
+        self._last_request_is_blocked = True
         self.connection.request(method, url, payload, headers)
 
         # timeout for request has to be set just before calling httplib.getresponse()
@@ -261,6 +260,7 @@ class HTTPWireProtocol:
             if timeout:
                 self._conn.settimeout(previous_timeout)
 
+        self._last_request_is_blocked = False
         return response
 
     def _has_unread_data(self):
diff --git a/tests/wpt/tests/tools/wptrunner/wptrunner/testharnessreport-content-shell.js b/tests/wpt/tests/tools/wptrunner/wptrunner/testharnessreport-content-shell.js
deleted file mode 100644
index 1e24fdbcfbf..00000000000
--- a/tests/wpt/tests/tools/wptrunner/wptrunner/testharnessreport-content-shell.js
+++ /dev/null
@@ -1,45 +0,0 @@
-(function() {
-    var props = {output:%(output)d, debug: %(debug)s};
-    setup(props);
-
-    // Some tests navigate away from the original URL as part of the
-    // functionality they exercise. In that case, `add_completion_callback(...)`
-    // uses the final `window.location` to report the test ID, which may not be
-    // correct [1].
-    //
-    // Persisting the original `window.location` with standard web platform APIs
-    // (e.g., `localStorage`) could interfere with the their tests, so this must
-    // be avoided. Unfortunately, there doesn't appear to be anything in content
-    // shell's protocol mode or Blink-specific `window.testRunner` or
-    // `window.internals` [2] that could help with this. As such, the driver
-    // simply downgrades a mismatched test ID to a logged warning instead of a
-    // harness error.
-    //
-    // [1] crbug.com/1418753
-    // [2] https://chromium.googlesource.com/chromium/src/+/refs/heads/main/docs/testing/writing_web_tests.md#Relying-on-Blink_Specific-Testing-APIs
-    const url = new URL(location.href);
-
-    testRunner.dumpAsText();
-    testRunner.waitUntilDone();
-    testRunner.setPopupBlockingEnabled(false);
-    testRunner.setDumpJavaScriptDialogs(false);
-    // Show `CONSOLE MESSAGE:` and `CONSOLE ERROR:` in stderr.
-    if (props.debug) {
-        testRunner.setDumpConsoleMessages(true);
-    }
-
-    add_completion_callback(function (tests, harness_status) {
-        const test_id = decodeURIComponent(url.pathname) + decodeURIComponent(url.search) + decodeURIComponent(url.hash);
-        const result_string = JSON.stringify([
-            test_id,
-            harness_status.status,
-            harness_status.message,
-            harness_status.stack,
-            tests.map(function(t) {
-                return [t.name, t.status, t.message, t.stack]
-            }),
-        ]);
-        testRunner.setCustomTextOutput(result_string);
-        testRunner.notifyDone();
-    });
-})();
diff --git a/tests/wpt/tests/webcodecs/audio-encoder-config.https.any.js b/tests/wpt/tests/webcodecs/audio-encoder-config.https.any.js
index a70bf28f80c..ad5d56ca492 100644
--- a/tests/wpt/tests/webcodecs/audio-encoder-config.https.any.js
+++ b/tests/wpt/tests/webcodecs/audio-encoder-config.https.any.js
@@ -56,6 +56,15 @@ const invalidConfigs = [
       bitrate: 6e9,
     },
   },
+  {
+    comment: 'Bit rate present but equal to zero',
+    config: {
+      codec: 'opus',
+      sampleRate: 8000,
+      numberOfChannels: 2,
+      bitrate: 0,
+    },
+  },
   {
     comment: 'Opus complexity too big',
     config: {
diff --git a/tests/wpt/tests/webcodecs/full-cycle-test.https.any.js b/tests/wpt/tests/webcodecs/full-cycle-test.https.any.js
index 8e1ae65bdca..a63edd04d75 100644
--- a/tests/wpt/tests/webcodecs/full-cycle-test.https.any.js
+++ b/tests/wpt/tests/webcodecs/full-cycle-test.https.any.js
@@ -149,7 +149,10 @@ async function runFullCycleTest(t, options) {
   const encoder_init = {
     output(chunk, metadata) {
       let config = metadata.decoderConfig;
-      if (config) {
+      // Issue a configure if there's a new config, or on the
+      // first chunk if testing rate control
+      if (!options.rateControl && config ||
+          options.rateControl && chunk.timestamp == 0) {
         config.hardwareAcceleration = encoder_config.hardwareAcceleration;
         encoder_color_space = config.colorSpace;
 
@@ -185,6 +188,11 @@ async function runFullCycleTest(t, options) {
 
     let keyframe = (i % 5 == 0);
     encoder.encode(frame, { keyFrame: keyframe });
+    if (i % 3 == 0 && options.rateControl) {
+      // reconfigure with a different rate
+      encoder_config.bitrate = encoder_config.bitrate * 0.9;
+      encoder.configure(encoder_config);
+    }
     frame.close();
   }
   await encoder.flush();
@@ -211,3 +219,7 @@ promise_test(async t => {
   if (ENCODER_CONFIG.hasEmbeddedColorSpace)
     return runFullCycleTest(t, {stripDecoderConfigColorSpace: true});
 }, 'Encoding and decoding cycle w/ stripped color space');
+
+promise_test(async t => {
+  return runFullCycleTest(t, {rateControl: true});
+}, 'Encoding and decoding cycle w/ rate control');
diff --git a/tests/wpt/tests/webcodecs/video-encoder-config.https.any.js b/tests/wpt/tests/webcodecs/video-encoder-config.https.any.js
index 8d554e4f4db..d61958919d7 100644
--- a/tests/wpt/tests/webcodecs/video-encoder-config.https.any.js
+++ b/tests/wpt/tests/webcodecs/video-encoder-config.https.any.js
@@ -51,6 +51,15 @@ const invalidConfigs = [
       height: 480,
     },
   },
+  {
+    comment: 'bitrate is present but zero',
+    config: {
+      codec: 'vp8',
+      width: 640,
+      height: 480,
+      bitrate: 0
+    },
+  },
 ];
 
 invalidConfigs.forEach(entry => {
diff --git a/tests/wpt/tests/webcodecs/videoFrame-copyTo-rgb.any.js b/tests/wpt/tests/webcodecs/videoFrame-copyTo-rgb.any.js
index 146b6756cb4..eb7351e048b 100644
--- a/tests/wpt/tests/webcodecs/videoFrame-copyTo-rgb.any.js
+++ b/tests/wpt/tests/webcodecs/videoFrame-copyTo-rgb.any.js
@@ -2,6 +2,19 @@
 // META: script=/webcodecs/videoFrame-utils.js
 // META: script=/webcodecs/video-encoder-utils.js
 
+const smpte170m = {
+  matrix: 'smpte170m',
+  primaries: 'smpte170m',
+  transfer: 'smpte170m',
+  fullRange: false
+};
+const bt709 = {
+  matrix: 'bt709',
+  primaries: 'bt709',
+  transfer: 'bt709',
+  fullRange: false
+};
+
 function compareColors(actual, expected, tolerance, msg) {
   let channel = ['R', 'G', 'B', 'A'];
   for (let i = 0; i < 4; i++) {
@@ -24,7 +37,7 @@ function rgb2yuv(r, g, b) {
   }
 }
 
-function makeI420Frames() {
+function makeI420Frames(colorSpace) {
   const kYellow = {r: 0xFF, g: 0xFF, b: 0x00};
   const kRed = {r: 0xFF, g: 0x00, b: 0x00};
   const kBlue = {r: 0x00, g: 0x00, b: 0xFF};
@@ -33,68 +46,39 @@ function makeI420Frames() {
   const kMagenta = {r: 0xFF, g: 0x00, b: 0xFF};
   const kBlack = {r: 0x00, g: 0x00, b: 0x00};
   const kWhite = {r: 0xFF, g: 0xFF, b: 0xFF};
-  const smpte170m = {
-    matrix: 'smpte170m',
-    primaries: 'smpte170m',
-    transfer: 'smpte170m',
-    fullRange: false
-  };
-  const bt709 = {
-    matrix: 'bt709',
-    primaries: 'bt709',
-    transfer: 'bt709',
-    fullRange: false
-  };
 
   const result = [];
   const init = {format: 'I420', timestamp: 0, codedWidth: 4, codedHeight: 4};
   const colors =
       [kYellow, kRed, kBlue, kGreen, kMagenta, kBlack, kWhite, kPink];
   const data = new Uint8Array(24);
-  for (let colorSpace of [null, smpte170m, bt709]) {
-    init.colorSpace = colorSpace;
+  init.colorSpace = colorSpace;
+  for (let color of colors) {
+    color = rgb2yuv(color.r, color.g, color.b);
+    data.fill(color.y, 0, 16);
+    data.fill(color.u, 16, 20);
+    data.fill(color.v, 20, 24);
     result.push(new VideoFrame(data, init));
-    for (let color of colors) {
-      color = rgb2yuv(color.r, color.g, color.b);
-      data.fill(color.y, 0, 16);
-      data.fill(color.u, 16, 20);
-      data.fill(color.v, 20, 24);
-      result.push(new VideoFrame(data, init));
-    }
   }
   return result;
 }
 
-function makeRGBXFrames() {
+function makeRGBXFrames(colorSpace) {
   const kYellow = 0xFFFF00;
   const kRed = 0xFF0000;
   const kBlue = 0x0000FF;
   const kGreen = 0x00FF00;
   const kBlack = 0x000000;
   const kWhite = 0xFFFFFF;
-  const smpte170m = {
-    matrix: 'smpte170m',
-    primaries: 'smpte170m',
-    transfer: 'smpte170m',
-    fullRange: false
-  };
-  const bt709 = {
-    matrix: 'bt709',
-    primaries: 'bt709',
-    transfer: 'bt709',
-    fullRange: false
-  };
 
   const result = [];
   const init = {format: 'RGBX', timestamp: 0, codedWidth: 4, codedHeight: 4};
   const colors = [kYellow, kRed, kBlue, kGreen, kBlack, kWhite];
   const data = new Uint32Array(16);
-  for (let colorSpace of [null, smpte170m, bt709]) {
-    init.colorSpace = colorSpace;
-    for (let color of colors) {
-      data.fill(color, 0, 16);
-      result.push(new VideoFrame(data, init));
-    }
+  init.colorSpace = colorSpace;
+  for (let color of colors) {
+    data.fill(color, 0, 16);
+    result.push(new VideoFrame(data, init));
   }
   return result;
 }
@@ -156,12 +140,15 @@ async function testFrame(frame, colorSpace, pixelFormat) {
 function test_4x4_I420_frames() {
   for (let colorSpace of ['srgb', 'display-p3']) {
     for (let pixelFormat of ['RGBA', 'RGBX', 'BGRA', 'BGRX']) {
-      promise_test(async t => {
-        for (let frame of makeI420Frames()) {
-          await testFrame(frame, colorSpace, pixelFormat);
-          frame.close();
-        }
-      }, `Convert 4x4 I420 frames to ${pixelFormat} / ${colorSpace}`);
+      for (let frameColorSpace of [null, smpte170m, bt709]) {
+        const frameColorSpaceName = frameColorSpace? frameColorSpace.primaries : "null";
+        promise_test(async t => {
+          for (let frame of makeI420Frames(frameColorSpace)) {
+            await testFrame(frame, colorSpace, pixelFormat);
+            frame.close();
+          }
+        }, `Convert 4x4 ${frameColorSpaceName} I420 frames to ${pixelFormat} / ${colorSpace}`);
+      }
     }
   }
 }
@@ -170,12 +157,15 @@ test_4x4_I420_frames();
 function test_4x4_RGB_frames() {
   for (let colorSpace of ['srgb', 'display-p3']) {
     for (let pixelFormat of ['RGBA', 'RGBX', 'BGRA', 'BGRX']) {
-      promise_test(async t => {
-        for (let frame of makeRGBXFrames()) {
-          await testFrame(frame, colorSpace, pixelFormat);
-          frame.close();
-        }
-      }, `Convert 4x4 RGBX frames to ${pixelFormat} / ${colorSpace}`);
+      for (let frameColorSpace of [null, smpte170m, bt709]) {
+        const frameColorSpaceName = frameColorSpace? frameColorSpace.primaries : "null";
+        promise_test(async t => {
+          for (let frame of makeRGBXFrames(frameColorSpace)) {
+            await testFrame(frame, colorSpace, pixelFormat);
+            frame.close();
+          }
+        }, `Convert 4x4 ${frameColorSpaceName} RGBX frames to ${pixelFormat} / ${colorSpace}`);
+      }
     }
   }
 }
diff --git a/tests/wpt/tests/webdriver/tests/bidi/browsing_context/close/prompt_unload.py b/tests/wpt/tests/webdriver/tests/bidi/browsing_context/close/prompt_unload.py
index 2dc241ba396..e7d88ad272d 100644
--- a/tests/wpt/tests/webdriver/tests/bidi/browsing_context/close/prompt_unload.py
+++ b/tests/wpt/tests/webdriver/tests/bidi/browsing_context/close/prompt_unload.py
@@ -51,7 +51,7 @@ async def test_prompt_unload_not_triggering_dialog(
     remove_listener()
 
 
-@pytest.mark.capabilities({"unhandledPromptBehavior": {'default': 'ignore'}})
+@pytest.mark.capabilities({"unhandledPromptBehavior": {'beforeUnload': 'ignore'}})
 @pytest.mark.parametrize("type_hint", ["window", "tab"])
 async def test_prompt_unload_triggering_dialog(
     bidi_session,
diff --git a/tests/wpt/tests/webdriver/tests/bidi/browsing_context/handle_user_prompt/handle_user_prompt.py b/tests/wpt/tests/webdriver/tests/bidi/browsing_context/handle_user_prompt/handle_user_prompt.py
index 5bbc616960f..9044f220bcc 100644
--- a/tests/wpt/tests/webdriver/tests/bidi/browsing_context/handle_user_prompt/handle_user_prompt.py
+++ b/tests/wpt/tests/webdriver/tests/bidi/browsing_context/handle_user_prompt/handle_user_prompt.py
@@ -112,7 +112,7 @@ async def test_prompt(
         assert result == {"type": "null"}
 
 
-@pytest.mark.capabilities({"unhandledPromptBehavior": {'default': 'ignore'}})
+@pytest.mark.capabilities({"unhandledPromptBehavior": {'beforeUnload': 'ignore'}})
 @pytest.mark.parametrize("accept", [True, False])
 async def test_beforeunload(
     bidi_session,
diff --git a/tests/wpt/tests/webdriver/tests/bidi/browsing_context/user_prompt_closed/beforeunload.py b/tests/wpt/tests/webdriver/tests/bidi/browsing_context/user_prompt_closed/beforeunload.py
index 6b2e788a058..ab16526fdb1 100644
--- a/tests/wpt/tests/webdriver/tests/bidi/browsing_context/user_prompt_closed/beforeunload.py
+++ b/tests/wpt/tests/webdriver/tests/bidi/browsing_context/user_prompt_closed/beforeunload.py
@@ -9,7 +9,7 @@ USER_PROMPT_CLOSED_EVENT = "browsingContext.userPromptClosed"
 USER_PROMPT_OPENED_EVENT = "browsingContext.userPromptOpened"
 
 
-@pytest.mark.capabilities({"unhandledPromptBehavior": {'default': 'ignore'}})
+@pytest.mark.capabilities({"unhandledPromptBehavior": {'beforeUnload': 'ignore'}})
 @pytest.mark.parametrize("accept", [False, True])
 async def test_beforeunload(
     bidi_session,
diff --git a/tests/wpt/tests/webdriver/tests/bidi/browsing_context/user_prompt_opened/user_prompt_opened.py b/tests/wpt/tests/webdriver/tests/bidi/browsing_context/user_prompt_opened/user_prompt_opened.py
index 3a995b15038..c24128004f7 100644
--- a/tests/wpt/tests/webdriver/tests/bidi/browsing_context/user_prompt_opened/user_prompt_opened.py
+++ b/tests/wpt/tests/webdriver/tests/bidi/browsing_context/user_prompt_opened/user_prompt_opened.py
@@ -202,3 +202,69 @@ async def test_iframe(
         "handler": "dismiss",
         "message": "in iframe",
     }
+
+
+@pytest.mark.parametrize("type_hint", ["tab", "window"])
+async def test_two_prompts(
+    bidi_session,
+    subscribe_events,
+    inline,
+    wait_for_event,
+    wait_for_future_safe,
+    type_hint,
+):
+    new_context = await bidi_session.browsing_context.create(type_hint=type_hint)
+    await subscribe_events(
+        events=[USER_PROMPT_OPENED_EVENT]
+    )
+    # Track all received browsingContext.userPromptOpened events in the events array
+    events = []
+
+    async def on_event(method, data):
+        events.append(data)
+
+    remove_listener = bidi_session.add_event_listener(
+        USER_PROMPT_OPENED_EVENT, on_event
+    )
+
+    on_first_event = wait_for_event(USER_PROMPT_OPENED_EVENT)
+
+    another_new_context = await bidi_session.browsing_context.create(
+        type_hint=type_hint
+    )
+
+    # Open a prompt in the first context.
+    await bidi_session.browsing_context.navigate(
+        context=new_context["context"],
+        url=inline("<script>window.alert('first tab')</script>"),
+    )
+
+    await wait_for_future_safe(on_first_event)
+
+    # Open a prompt in the second context.
+    await bidi_session.browsing_context.navigate(
+        context=another_new_context["context"],
+        url=inline("<script>window.confirm('second tab')</script>"),
+    )
+
+    on_second_event = wait_for_event(USER_PROMPT_OPENED_EVENT)
+
+    await wait_for_future_safe(on_second_event)
+
+    assert len(events) == 2
+
+    assert events == [{
+        "context": new_context["context"],
+        "type": "alert",
+        "handler": "dismiss",
+        "message": "first tab",
+    }, {
+        "context": another_new_context["context"],
+        "type": "confirm",
+        "handler": "dismiss",
+        "message": "second tab",
+    }]
+
+    remove_listener()
+    await bidi_session.browsing_context.close(context=new_context["context"])
+    await bidi_session.browsing_context.close(context=another_new_context["context"])
diff --git a/tests/wpt/tests/webdriver/tests/bidi/integration/cookies_with_network_events.py b/tests/wpt/tests/webdriver/tests/bidi/integration/cookies_with_network_events.py
index 16ca358e23b..30ba8e3bd7b 100644
--- a/tests/wpt/tests/webdriver/tests/bidi/integration/cookies_with_network_events.py
+++ b/tests/wpt/tests/webdriver/tests/bidi/integration/cookies_with_network_events.py
@@ -118,7 +118,7 @@ async def test_fetch(
     # Navigate away from about:blank to make sure document.cookies can be used.
     await bidi_session.browsing_context.navigate(
         context=new_tab["context"],
-        url=url("/webdriver/tests/bidi/support/empty.html"),
+        url=url("/webdriver/tests/bidi/network/support/empty.html"),
         wait="complete"
     )
 
diff --git a/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_bypass/__init__.py b/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_behavior/__init__.py
similarity index 100%
rename from tests/wpt/tests/webdriver/tests/bidi/network/set_cache_bypass/__init__.py
rename to tests/wpt/tests/webdriver/tests/bidi/network/set_cache_behavior/__init__.py
diff --git a/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_behavior/conftest.py b/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_behavior/conftest.py
new file mode 100644
index 00000000000..1f12c9fcb84
--- /dev/null
+++ b/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_behavior/conftest.py
@@ -0,0 +1,33 @@
+import pytest_asyncio
+import random
+
+from .. import RESPONSE_COMPLETED_EVENT
+
+
+@pytest_asyncio.fixture
+async def is_request_from_cache(
+    wait_for_event, fetch, wait_for_future_safe, top_context
+):
+    async def is_request_from_cache(url, context=top_context):
+        on_response_completed = wait_for_event(RESPONSE_COMPLETED_EVENT)
+        await fetch(url, context=context)
+        event = await wait_for_future_safe(on_response_completed)
+
+        return event["response"]["fromCache"]
+
+    return is_request_from_cache
+
+
+@pytest_asyncio.fixture
+async def is_cache_enabled_for_context(fetch, top_context, url, is_request_from_cache):
+    async def is_cache_enabled_for_context(context=top_context):
+        cached_url = url(
+            f"/webdriver/tests/support/http_handlers/cached.py?status=200&nocache={random.random()}"
+        )
+
+        # Make first request to fill up the cache.
+        await is_request_from_cache(url=cached_url, context=context)
+
+        return await is_request_from_cache(url=cached_url, context=context)
+
+    return is_cache_enabled_for_context
diff --git a/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_behavior/contexts.py b/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_behavior/contexts.py
new file mode 100644
index 00000000000..5872a7d12e0
--- /dev/null
+++ b/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_behavior/contexts.py
@@ -0,0 +1,204 @@
+import pytest
+
+from .. import RESPONSE_COMPLETED_EVENT
+
+pytestmark = pytest.mark.asyncio
+
+
+async def test_one_context(
+    bidi_session,
+    setup_network_test,
+    top_context,
+    new_tab,
+    inline,
+    is_cache_enabled_for_context,
+):
+    await bidi_session.browsing_context.navigate(
+        context=new_tab["context"],
+        url=inline("foo"),
+        wait="complete",
+    )
+
+    await setup_network_test(
+        events=[RESPONSE_COMPLETED_EVENT],
+        contexts=[top_context["context"], new_tab["context"]],
+    )
+
+    # Make sure that cache is enabled by default.
+    assert await is_cache_enabled_for_context(top_context) is True
+    assert await is_cache_enabled_for_context(new_tab) is True
+
+    # Disable cache only in one context.
+    await bidi_session.network.set_cache_behavior(
+        cache_behavior="bypass", contexts=[new_tab["context"]]
+    )
+
+    assert await is_cache_enabled_for_context(top_context) is True
+    assert await is_cache_enabled_for_context(new_tab) is False
+
+    # Reset to default behavior.
+    await bidi_session.network.set_cache_behavior(
+        cache_behavior="default", contexts=[new_tab["context"]]
+    )
+
+
+@pytest.mark.parametrize("type_hint", ["tab", "window"])
+async def test_new_context(
+    bidi_session,
+    setup_network_test,
+    top_context,
+    inline,
+    is_cache_enabled_for_context,
+    type_hint,
+):
+    await setup_network_test(events=[RESPONSE_COMPLETED_EVENT])
+
+    # Make sure that cache is enabled by default.
+    assert await is_cache_enabled_for_context() is True
+
+    # Disable cache only in one context.
+    await bidi_session.network.set_cache_behavior(
+        cache_behavior="bypass", contexts=[top_context["context"]]
+    )
+
+    assert await is_cache_enabled_for_context() is False
+
+    # Create a new tab.
+    new_context = await bidi_session.browsing_context.create(type_hint=type_hint)
+
+    await bidi_session.browsing_context.navigate(
+        context=new_context["context"],
+        url=inline("<div>foo</div>"),
+        wait="complete",
+    )
+
+    # Make sure that the new context still has cache enabled.
+    assert await is_cache_enabled_for_context(context=new_context) is True
+
+    # Reset to default behavior.
+    await bidi_session.network.set_cache_behavior(
+        cache_behavior="default", contexts=[top_context["context"]]
+    )
+
+
+async def test_disable_globally_after_disable_for_context(
+    bidi_session,
+    setup_network_test,
+    top_context,
+    new_tab,
+    inline,
+    is_cache_enabled_for_context,
+):
+    await bidi_session.browsing_context.navigate(
+        context=new_tab["context"],
+        url=inline("foo"),
+        wait="complete",
+    )
+
+    await setup_network_test(
+        events=[RESPONSE_COMPLETED_EVENT],
+        contexts=[top_context["context"], new_tab["context"]],
+    )
+
+    # Make sure that cache is enabled by default.
+    assert await is_cache_enabled_for_context() is True
+    assert await is_cache_enabled_for_context(context=new_tab) is True
+
+    # Disable cache only in one context.
+    await bidi_session.network.set_cache_behavior(
+        cache_behavior="bypass", contexts=[new_tab["context"]]
+    )
+
+    assert await is_cache_enabled_for_context() is True
+    assert await is_cache_enabled_for_context(context=new_tab) is False
+
+    # Disable cache globally.
+    await bidi_session.network.set_cache_behavior(cache_behavior="bypass")
+
+    # Make sure that cache is disabled for both contexts.
+    assert await is_cache_enabled_for_context() is False
+    assert await is_cache_enabled_for_context(context=new_tab) is False
+
+    # Reset to default behavior.
+    await bidi_session.network.set_cache_behavior(cache_behavior="default")
+
+
+async def test_enable_globally_after_disable_for_context(
+    bidi_session,
+    setup_network_test,
+    top_context,
+    new_tab,
+    inline,
+    is_cache_enabled_for_context,
+):
+    await bidi_session.browsing_context.navigate(
+        context=new_tab["context"],
+        url=inline("foo"),
+        wait="complete",
+    )
+
+    await setup_network_test(
+        events=[RESPONSE_COMPLETED_EVENT],
+        contexts=[top_context["context"], new_tab["context"]],
+    )
+
+    # Make sure that cache is enabled by default.
+    assert await is_cache_enabled_for_context(context=top_context) is True
+    assert await is_cache_enabled_for_context(context=new_tab) is True
+
+    # Disable cache only in one context.
+    await bidi_session.network.set_cache_behavior(
+        cache_behavior="bypass", contexts=[new_tab["context"]]
+    )
+
+    assert await is_cache_enabled_for_context(context=top_context) is True
+    assert await is_cache_enabled_for_context(context=new_tab) is False
+
+    # Enable cache globally.
+    await bidi_session.network.set_cache_behavior(cache_behavior="default")
+
+    # Make sure that cache is enabled for both contexts.
+    assert await is_cache_enabled_for_context(context=top_context) is True
+    assert await is_cache_enabled_for_context(context=new_tab) is True
+
+
+async def test_setting_cache_to_contexts_after_global_update(
+    bidi_session,
+    setup_network_test,
+    top_context,
+    new_tab,
+    inline,
+    is_cache_enabled_for_context
+):
+    await bidi_session.browsing_context.navigate(
+        context=new_tab["context"],
+        url=inline("foo"),
+        wait="complete",
+    )
+
+    await setup_network_test(
+        events=[RESPONSE_COMPLETED_EVENT],
+        contexts=[top_context["context"], new_tab["context"]],
+    )
+
+    # Make sure that cache is enabled by default.
+    assert await is_cache_enabled_for_context(context=top_context) is True
+    assert await is_cache_enabled_for_context(context=new_tab) is True
+
+    # Disable cache globally.
+    await bidi_session.network.set_cache_behavior(cache_behavior="bypass")
+
+    assert await is_cache_enabled_for_context(context=top_context) is False
+    assert await is_cache_enabled_for_context(context=new_tab) is False
+
+    # Enable cache for one context.
+    await bidi_session.network.set_cache_behavior(
+        cache_behavior="default", contexts=[new_tab["context"]]
+    )
+
+    # Make sure that cache is disabled only for one context.
+    assert await is_cache_enabled_for_context(context=top_context) is False
+    assert await is_cache_enabled_for_context(context=new_tab) is True
+
+    # Reset to default behavior.
+    await bidi_session.network.set_cache_behavior(cache_behavior="default")
diff --git a/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_behavior/invalid.py b/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_behavior/invalid.py
new file mode 100644
index 00000000000..921db569d4f
--- /dev/null
+++ b/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_behavior/invalid.py
@@ -0,0 +1,39 @@
+import pytest
+import webdriver.bidi.error as error
+
+
+pytestmark = pytest.mark.asyncio
+
+
+@pytest.mark.parametrize("value", [None, False, 42, {}, []])
+async def test_params_cache_behavior_invalid_type(bidi_session, value):
+    with pytest.raises(error.InvalidArgumentException):
+        await bidi_session.network.set_cache_behavior(cache_behavior=value)
+
+
+@pytest.mark.parametrize("value", ["bypas", "DEFAULT"])
+async def test_params_cache_behavior_invalid_value(bidi_session, value):
+    with pytest.raises(error.InvalidArgumentException):
+        await bidi_session.network.set_cache_behavior(cache_behavior=value)
+
+
+@pytest.mark.parametrize("value", ["foo", 42, False, {}])
+async def test_params_contexts_invalid_type(bidi_session, value):
+    with pytest.raises(error.InvalidArgumentException):
+        await bidi_session.network.set_cache_behavior(cache_behavior="bypass", contexts=value)
+
+
+async def test_params_contexts_invalid_value_empty_array(bidi_session):
+    with pytest.raises(error.InvalidArgumentException):
+        await bidi_session.network.set_cache_behavior(cache_behavior="bypass", contexts=[])
+
+
+@pytest.mark.parametrize("value", [None, 42, False, {}, []])
+async def test_params_contexts_invalid_array_element_type(bidi_session, value):
+    with pytest.raises(error.InvalidArgumentException):
+        await bidi_session.network.set_cache_behavior(cache_behavior="bypass", contexts=[value])
+
+
+async def test_params_contexts_invalid_array_element_value(bidi_session):
+    with pytest.raises(error.NoSuchFrameException):
+        await bidi_session.network.set_cache_behavior(cache_behavior="bypass", contexts=["foo"])
diff --git a/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_behavior/set_cache_behavior.py b/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_behavior/set_cache_behavior.py
new file mode 100644
index 00000000000..0d55d520c96
--- /dev/null
+++ b/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_behavior/set_cache_behavior.py
@@ -0,0 +1,51 @@
+import pytest
+
+from .. import RESPONSE_COMPLETED_EVENT
+
+pytestmark = pytest.mark.asyncio
+
+
+async def test_set_cache_behavior(
+    bidi_session, setup_network_test, url, is_cache_enabled_for_context
+):
+    await setup_network_test(events=[RESPONSE_COMPLETED_EVENT])
+
+    # Make sure that cache is enabled by default.
+    assert await is_cache_enabled_for_context() is True
+
+    await bidi_session.network.set_cache_behavior(cache_behavior="bypass")
+
+    assert await is_cache_enabled_for_context() is False
+
+    await bidi_session.network.set_cache_behavior(cache_behavior="default")
+
+    assert await is_cache_enabled_for_context() is True
+
+
+@pytest.mark.parametrize("type_hint", ["tab", "window"])
+async def test_new_context(
+    bidi_session, setup_network_test, inline, is_cache_enabled_for_context, type_hint
+):
+    await setup_network_test(events=[RESPONSE_COMPLETED_EVENT])
+
+    # Make sure that cache is enabled by default.
+    assert await is_cache_enabled_for_context() is True
+
+    await bidi_session.network.set_cache_behavior(cache_behavior="bypass")
+
+    assert await is_cache_enabled_for_context() is False
+
+    # Create a new tab.
+    new_context = await bidi_session.browsing_context.create(type_hint=type_hint)
+
+    await bidi_session.browsing_context.navigate(
+        context=new_context["context"],
+        url=inline("<div>foo</div>"),
+        wait="complete",
+    )
+
+    # Make sure that the new context still has cache disabled.
+    assert await is_cache_enabled_for_context(new_context) is False
+
+    # Reset to default behavior.
+    await bidi_session.network.set_cache_behavior(cache_behavior="default")
diff --git a/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_bypass/conftest.py b/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_bypass/conftest.py
deleted file mode 100644
index 969641b8fd2..00000000000
--- a/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_bypass/conftest.py
+++ /dev/null
@@ -1,17 +0,0 @@
-import pytest_asyncio
-
-from .. import RESPONSE_COMPLETED_EVENT
-
-
-@pytest_asyncio.fixture
-async def is_request_from_cache(
-    wait_for_event, fetch, wait_for_future_safe, top_context
-):
-    async def is_request_from_cache(url, context=top_context):
-        on_response_completed = wait_for_event(RESPONSE_COMPLETED_EVENT)
-        await fetch(url, context=context)
-        event = await wait_for_future_safe(on_response_completed)
-
-        return event["response"]["fromCache"]
-
-    return is_request_from_cache
diff --git a/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_bypass/contexts_tentative.py b/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_bypass/contexts_tentative.py
deleted file mode 100644
index 946d6d9a7eb..00000000000
--- a/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_bypass/contexts_tentative.py
+++ /dev/null
@@ -1,99 +0,0 @@
-import pytest
-import random
-
-from .. import RESPONSE_COMPLETED_EVENT
-
-pytestmark = pytest.mark.asyncio
-
-
-async def test_one_context(
-    bidi_session,
-    setup_network_test,
-    top_context,
-    new_tab,
-    url,
-    inline,
-    is_request_from_cache,
-):
-    await bidi_session.browsing_context.navigate(
-        context=new_tab["context"],
-        url=inline("foo"),
-        wait="complete",
-    )
-
-    await setup_network_test(
-        events=[RESPONSE_COMPLETED_EVENT],
-        contexts=[top_context["context"], new_tab["context"]],
-    )
-
-    cached_url = url(
-        f"/webdriver/tests/support/http_handlers/cached.py?status=200&nocache={random.random()}"
-    )
-
-    # The first request/response is used to fill the browser cache,
-    # so we expect fromCache to be False here.
-    assert await is_request_from_cache(url=cached_url, context=top_context) is False
-
-    # In the second tab it will request from cache.
-    assert await is_request_from_cache(url=cached_url, context=new_tab) is True
-
-    # Disable cache only in one context.
-    await bidi_session.network.set_cache_bypass(
-        bypass=True, contexts=[new_tab["context"]]
-    )
-
-    assert await is_request_from_cache(url=cached_url, context=top_context) is True
-    assert await is_request_from_cache(url=cached_url, context=new_tab) is False
-
-    # Reset to default behavior.
-    await bidi_session.network.set_cache_bypass(
-        bypass=False, contexts=[new_tab["context"]]
-    )
-
-
-@pytest.mark.parametrize("type_hint", ["tab", "window"])
-async def test_new_context(
-    bidi_session,
-    setup_network_test,
-    top_context,
-    url,
-    inline,
-    is_request_from_cache,
-    type_hint,
-):
-    await setup_network_test(events=[RESPONSE_COMPLETED_EVENT])
-
-    cached_url = url(
-        f"/webdriver/tests/support/http_handlers/cached.py?status=200&nocache={random.random()}"
-    )
-
-    # The first request/response is used to fill the browser cache,
-    # so we expect fromCache to be False here.
-    assert await is_request_from_cache(url=cached_url) is False
-
-    # In the second tab it will request from cache.
-    assert await is_request_from_cache(url=cached_url) is True
-
-    # Disable cache only in one context.
-    await bidi_session.network.set_cache_bypass(
-        bypass=True, contexts=[top_context["context"]]
-    )
-
-    assert await is_request_from_cache(url=cached_url, context=top_context) is False
-
-    # Create a new tab.
-    new_context = await bidi_session.browsing_context.create(type_hint=type_hint)
-
-    await bidi_session.browsing_context.navigate(
-        context=new_context["context"],
-        url=inline("<div>foo</div>"),
-        wait="complete",
-    )
-
-    # Make sure that the new context still has cache enabled.
-    assert await is_request_from_cache(cached_url, context=new_context) is True
-
-    # Reset to default behavior.
-    await bidi_session.network.set_cache_bypass(
-        bypass=False, contexts=[top_context["context"]]
-    )
diff --git a/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_bypass/invalid_tentative.py b/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_bypass/invalid_tentative.py
deleted file mode 100644
index 678d5d313f8..00000000000
--- a/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_bypass/invalid_tentative.py
+++ /dev/null
@@ -1,32 +0,0 @@
-import pytest
-import webdriver.bidi.error as error
-
-pytestmark = pytest.mark.asyncio
-
-
-@pytest.mark.parametrize("value", [None, "foo", 42, {}, []])
-async def test_params_bypass_invalid_type(bidi_session, value):
-    with pytest.raises(error.InvalidArgumentException):
-        await bidi_session.network.set_cache_bypass(bypass=value)
-
-
-@pytest.mark.parametrize("value", ["foo", 42, False, {}])
-async def test_params_contexts_invalid_type(bidi_session, value):
-    with pytest.raises(error.InvalidArgumentException):
-        await bidi_session.network.set_cache_bypass(bypass=True, contexts=value)
-
-
-async def test_params_contexts_invalid_value_empty_array(bidi_session):
-    with pytest.raises(error.InvalidArgumentException):
-        await bidi_session.network.set_cache_bypass(bypass=True, contexts=[])
-
-
-@pytest.mark.parametrize("value", [None, 42, False, {}, []])
-async def test_params_contexts_invalid_array_element_type(bidi_session, value):
-    with pytest.raises(error.InvalidArgumentException):
-        await bidi_session.network.set_cache_bypass(bypass=True, contexts=[value])
-
-
-async def test_params_contexts_invalid_array_element_value(bidi_session):
-    with pytest.raises(error.NoSuchFrameException):
-        await bidi_session.network.set_cache_bypass(bypass=True, contexts=["foo"])
diff --git a/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_bypass/set_cache_bypass_tentative.py b/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_bypass/set_cache_bypass_tentative.py
deleted file mode 100644
index 42166ef253b..00000000000
--- a/tests/wpt/tests/webdriver/tests/bidi/network/set_cache_bypass/set_cache_bypass_tentative.py
+++ /dev/null
@@ -1,68 +0,0 @@
-import pytest
-import random
-
-from .. import RESPONSE_COMPLETED_EVENT
-
-pytestmark = pytest.mark.asyncio
-
-
-async def test_set_cache_bypass(
-    bidi_session, setup_network_test, url, is_request_from_cache
-):
-    await setup_network_test(events=[RESPONSE_COMPLETED_EVENT])
-
-    cached_url = url(
-        f"/webdriver/tests/support/http_handlers/cached.py?status=200&nocache={random.random()}"
-    )
-
-    # The first request/response is used to fill the browser cache,
-    # so we expect fromCache to be False here.
-    assert await is_request_from_cache(cached_url) is False
-
-    # The second request for the same URL has to be read from the local cache.
-    assert await is_request_from_cache(cached_url) is True
-
-    await bidi_session.network.set_cache_bypass(bypass=True)
-
-    assert await is_request_from_cache(cached_url) is False
-
-    await bidi_session.network.set_cache_bypass(bypass=False)
-
-    assert await is_request_from_cache(cached_url) is True
-
-
-@pytest.mark.parametrize("type_hint", ["tab", "window"])
-async def test_new_context(
-    bidi_session, setup_network_test, url, inline, is_request_from_cache, type_hint
-):
-    await setup_network_test(events=[RESPONSE_COMPLETED_EVENT])
-
-    cached_url = url(
-        f"/webdriver/tests/support/http_handlers/cached.py?status=200&nocache={random.random()}"
-    )
-
-    # The first request/response is used to fill the browser cache,
-    # so we expect fromCache to be False here.
-    assert await is_request_from_cache(cached_url) is False
-
-    # The second request for the same URL has to be read from the local cache.
-    assert await is_request_from_cache(cached_url) is True
-
-    await bidi_session.network.set_cache_bypass(bypass=True)
-
-    assert await is_request_from_cache(cached_url) is False
-
-    # Create a new tab.
-    new_context = await bidi_session.browsing_context.create(type_hint=type_hint)
-
-    await bidi_session.browsing_context.navigate(
-        context=new_context["context"],
-        url=inline("<div>foo</div>"),
-        wait="complete",
-    )
-
-    # Make sure that the new context still has cache disabled.
-    assert await is_request_from_cache(cached_url, context=new_context) is False
-
-    # Reset to default behavior.
-    await bidi_session.network.set_cache_bypass(bypass=False)
diff --git a/tests/wpt/tests/webdriver/tests/classic/new_session/unhandled_prompt_behavior.py b/tests/wpt/tests/webdriver/tests/classic/new_session/unhandled_prompt_behavior.py
index 2df69b131ff..05b0f930916 100644
--- a/tests/wpt/tests/webdriver/tests/classic/new_session/unhandled_prompt_behavior.py
+++ b/tests/wpt/tests/webdriver/tests/classic/new_session/unhandled_prompt_behavior.py
@@ -90,13 +90,13 @@ def test_unhandled_prompt_behavior_as_string(
     [
         (  # Check the default behavior with no handlers defined
             {},
-            "dismiss and notify",
+            {},
             True,
             True,
         ),
         (  # Check the default behavior with a custom value defined
             {"default": "accept"},
-            "accept",
+            {"default": "accept"},
             True,
             False,
         ),
@@ -155,11 +155,7 @@ def test_unhandled_prompt_behavior_as_object(
         }
     )
     value = assert_success(response)
-    if prompt == "default":
-        # For a single default handler the capability is serialized as a string
-        assert value["capabilities"]["unhandledPromptBehavior"] == handler
-    else:
-        assert value["capabilities"]["unhandledPromptBehavior"] == {prompt: handler}
+    assert value["capabilities"]["unhandledPromptBehavior"] == {prompt: handler}
 
 
 @pytest.mark.parametrize("handler", PROMPT_HANDLERS)
diff --git a/tests/wpt/tests/webnn/resources/test_data/conv_transpose2d.json b/tests/wpt/tests/webnn/resources/test_data/conv_transpose2d.json
index d15c4a84615..ba25e04094c 100644
--- a/tests/wpt/tests/webnn/resources/test_data/conv_transpose2d.json
+++ b/tests/wpt/tests/webnn/resources/test_data/conv_transpose2d.json
@@ -296,6 +296,55 @@
         "type": "float32"
       }
     },
+    {
+      "name": "convTranspose2d options.padding is the same upper padding",
+      "inputs": {
+        "input": {
+          "shape": [1, 3, 3, 1],
+          "data": [
+            0.5, 0.5, 0.5,
+            0.5, 0.5, 0.5,
+            0.5, 0.5, 0.5
+          ],
+          "type": "float32"
+        },
+        "filter": {
+          "shape": [2, 3, 3, 1],
+          "data": [
+            1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0,
+            1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
+          ],
+          "type": "float32",
+          "constant": true
+        }
+      },
+      "options": {
+        "outputSizes": [6, 6],
+        "groups": 1,
+        "strides": [2, 2],
+        "dilations": [1, 1],
+        "padding": [0, 1, 0, 1],
+        "filterLayout": "ohwi",
+        "inputLayout": "nhwc"
+      },
+      "expected": {
+        "shape": [1, 6, 6, 2],
+        "data": [
+          0.5, 0.5, 0.5, 0.5, 1.0, 1.0, 0.5,
+          0.5, 1.0, 1.0, 0.5, 0.5, 0.5, 0.5,
+          0.5, 0.5, 1.0, 1.0, 0.5, 0.5, 1.0,
+          1.0, 0.5, 0.5, 1.0, 1.0, 1.0, 1.0,
+          2.0, 2.0, 1.0, 1.0, 2.0, 2.0, 1.0,
+          1.0, 0.5, 0.5, 0.5, 0.5, 1.0, 1.0,
+          0.5, 0.5, 1.0, 1.0, 0.5, 0.5, 1.0,
+          1.0, 1.0, 1.0, 2.0, 2.0, 1.0, 1.0,
+          2.0, 2.0, 1.0, 1.0, 0.5, 0.5, 0.5,
+          0.5, 1.0, 1.0, 0.5, 0.5, 1.0, 1.0,
+          0.5, 0.5
+        ],
+        "type": "float32"
+      }
+    },
     {
       "name": "convTranspose2d float32 4D input and filter tensors options.strides",
       "inputs": {
diff --git a/tests/wpt/tests/webnn/resources/utils.js b/tests/wpt/tests/webnn/resources/utils.js
index b8a017fb44b..5008c008e68 100644
--- a/tests/wpt/tests/webnn/resources/utils.js
+++ b/tests/wpt/tests/webnn/resources/utils.js
@@ -1287,22 +1287,6 @@ const testWriteWebNNBuffer = (testName) => {
             ml_buffer, new Uint8Array(sizeOfDescriptor(descriptor))));
   }, `${testName} / destroy`);
 
-  promise_test(async () => {
-    const descriptor = {dataType: 'int32', dimensions: [2, 2]};
-    let ml_buffer = createBuffer(ml_context, descriptor);
-
-    // MLBuffer was unsupported for the deviceType.
-    if (ml_buffer === undefined) {
-      return;
-    }
-
-    const array_buffer = new ArrayBuffer(sizeOfDescriptor(descriptor));
-    const detached_buffer = array_buffer.transfer();
-    assert_true(array_buffer.detached, 'array buffer should be detached.');
-
-    ml_context.writeBuffer(ml_buffer, array_buffer);
-  }, `${testName} / detached`);
-
   promise_test(async () => {
     const bufferDescriptor = {dataType: 'int32', dimensions: [2, 3]};
     let ml_buffer = createBuffer(ml_context, bufferDescriptor);
@@ -1397,26 +1381,6 @@ const testReadWebNNBuffer = (testName) => {
         ml_context, ml_buffer, Uint8Array.from([0xBB, 0xBB, 0xAA, 0xAA]));
   }, `${testName} / src_offset_only`);
 
-  promise_test(async () => {
-    let ml_buffer =
-        createBuffer(ml_context, {dataType: 'int32', dimensions: [1]});
-
-    // MLBuffer was unsupported for the deviceType.
-    if (ml_buffer === undefined) {
-      return;
-    }
-
-    // Initialize the buffer.
-    const input_data = [0xAA, 0xAA, 0xAA, 0xAA];
-    ml_context.writeBuffer(ml_buffer, Uint8Array.from(input_data));
-
-    // Writing zero bytes at the end of the buffer.
-    ml_context.writeBuffer(
-        ml_buffer, Uint32Array.from([0xBBBBBBBB]), /*srcOffset=*/ 1);
-    await assert_buffer_data_equals(
-        ml_context, ml_buffer, Uint8Array.from(input_data));
-  }, `${testName} / zero_write`);
-
   promise_test(async () => {
     let ml_buffer =
         createBuffer(ml_context, {dataType: 'int32', dimensions: [1]});
diff --git a/tests/wpt/tests/webnn/validation_tests/convTranspose2d.https.any.js b/tests/wpt/tests/webnn/validation_tests/convTranspose2d.https.any.js
index c4717a7c538..f7cf4b3200c 100644
--- a/tests/wpt/tests/webnn/validation_tests/convTranspose2d.https.any.js
+++ b/tests/wpt/tests/webnn/validation_tests/convTranspose2d.https.any.js
@@ -445,6 +445,26 @@ const tests = [
       outputSizes: [1, 2, 10, 8],
     },
   },
+  {
+    name:
+        '[convTranspose2d] Throw if outputSizes[0] is not greater than 0.',
+    input: {dataType: 'float32', dimensions: [1, 1, 3, 3]},
+    filter: {dataType: 'float32', dimensions: [1, 2, 3, 3]},
+    options: {
+      strides: [3, 2],
+      outputSizes: [0, 7],
+    },
+  },
+  {
+    name:
+        '[convTranspose2d] Throw if outputSizes[1] is not greater than 0.',
+    input: {dataType: 'float32', dimensions: [1, 1, 3, 3]},
+    filter: {dataType: 'float32', dimensions: [1, 2, 3, 3]},
+    options: {
+      strides: [3, 2],
+      outputSizes: [9, 0],
+    },
+  },
   {
     name: '[convTranspose2d] Throw if the padding height is too large.',
     input: {dataType: 'float32', dimensions: [1, 1, 2, 2]},
diff --git a/tests/wpt/tests/webnn/validation_tests/gru.https.any.js b/tests/wpt/tests/webnn/validation_tests/gru.https.any.js
index b1b576e96d0..2b85ce23144 100644
--- a/tests/wpt/tests/webnn/validation_tests/gru.https.any.js
+++ b/tests/wpt/tests/webnn/validation_tests/gru.https.any.js
@@ -298,7 +298,7 @@ tests.forEach(
           });
         }
         if (test.options.recurrentBias) {
-          options.bias = builder.input('recurrentBias', {
+          options.recurrentBias = builder.input('recurrentBias', {
             dataType: test.options.recurrentBias.dataType,
             dimensions: test.options.recurrentBias.dimensions
           });
diff --git a/tests/wpt/tests/webnn/validation_tests/gruCell.https.any.js b/tests/wpt/tests/webnn/validation_tests/gruCell.https.any.js
index 0465928d514..e37c9ec5209 100644
--- a/tests/wpt/tests/webnn/validation_tests/gruCell.https.any.js
+++ b/tests/wpt/tests/webnn/validation_tests/gruCell.https.any.js
@@ -324,7 +324,7 @@ tests.forEach(
                 });
             }
             if (test.options.recurrentBias) {
-                options.bias = builder.input('recurrentBias', {
+                options.recurrentBias = builder.input('recurrentBias', {
                     dataType: test.options.recurrentBias.dataType,
                     dimensions: test.options.recurrentBias.dimensions
                 });
diff --git a/tests/wpt/tests/webnn/validation_tests/lstm.https.any.js b/tests/wpt/tests/webnn/validation_tests/lstm.https.any.js
index 2a3eaa1c202..06834b39604 100644
--- a/tests/wpt/tests/webnn/validation_tests/lstm.https.any.js
+++ b/tests/wpt/tests/webnn/validation_tests/lstm.https.any.js
@@ -284,7 +284,7 @@ tests.forEach(
           });
         }
         if (test.options.recurrentBias) {
-          options.bias = builder.input('recurrentBias', {
+          options.recurrentBias = builder.input('recurrentBias', {
             dataType: test.options.recurrentBias.dataType,
             dimensions: test.options.recurrentBias.dimensions
           });
diff --git a/tests/wpt/tests/webnn/validation_tests/lstmCell.https.any.js b/tests/wpt/tests/webnn/validation_tests/lstmCell.https.any.js
index d4031b07b24..6b7bd1958b3 100644
--- a/tests/wpt/tests/webnn/validation_tests/lstmCell.https.any.js
+++ b/tests/wpt/tests/webnn/validation_tests/lstmCell.https.any.js
@@ -560,7 +560,7 @@ tests.forEach(
           });
         }
         if (test.options.recurrentBias) {
-          options.bias = builder.input('recurrentBias', {
+          options.recurrentBias = builder.input('recurrentBias', {
             dataType: test.options.recurrentBias.dataType,
             dimensions: test.options.recurrentBias.dimensions
           });
diff --git a/tests/wpt/tests/webnn/validation_tests/pooling.https.any.js b/tests/wpt/tests/webnn/validation_tests/pooling.https.any.js
index 08a78f25baf..6d21f3d52f1 100644
--- a/tests/wpt/tests/webnn/validation_tests/pooling.https.any.js
+++ b/tests/wpt/tests/webnn/validation_tests/pooling.https.any.js
@@ -161,6 +161,26 @@ const tests = [
       outputSizes: [1, 2, 4, 4],
     },
   },
+  {
+    name: 'Throw if outputSizes[0] is not greater than 0.',
+    input: {dataType: 'float32', dimensions: [1, 2, 5, 5]},
+    options: {
+      windowDimensions: [2, 2],
+      padding: [2, 2, 2, 2],
+      strides: [2, 2],
+      outputSizes: [0, 4],
+    },
+  },
+  {
+    name: 'Throw if outputSizes[1] is not greater than 0.',
+    input: {dataType: 'float32', dimensions: [1, 2, 5, 5]},
+    options: {
+      windowDimensions: [2, 2],
+      padding: [2, 2, 2, 2],
+      strides: [2, 2],
+      outputSizes: [4, 0],
+    },
+  },
   {
     name: 'Throw if the length of window dimensions is not 2.',
     input: {dataType: 'float32', dimensions: [1, 2, 5, 5]},
diff --git a/tests/wpt/tests/webnn/validation_tests/resample2d.https.any.js b/tests/wpt/tests/webnn/validation_tests/resample2d.https.any.js
index cc52cf97f4f..0c6a475e878 100644
--- a/tests/wpt/tests/webnn/validation_tests/resample2d.https.any.js
+++ b/tests/wpt/tests/webnn/validation_tests/resample2d.https.any.js
@@ -87,6 +87,16 @@ const tests = [
     input: {dataType: 'float32', dimensions: [1, 1, 2, 4]},
     options: {sizes: [1, 1, 4, 6]},
   },
+  {
+    name: '[resample2d] Throw if sizes[0] is not a valid dimension',
+    input: {dataType: 'float32', dimensions: [1, 1, 2, 4]},
+    options: {sizes: [0, 1]},
+  },
+  {
+    name: '[resample2d] Throw if sizes[1] is not a valid dimension',
+    input: {dataType: 'float32', dimensions: [1, 1, 2, 4]},
+    options: {sizes: [1, 0]},
+  },
   {
     name: '[resample2d] Throw if input data type is not floating type',
     input: {dataType: 'int32', dimensions: [1, 1, 2, 4]},
diff --git a/tests/wpt/tests/webnn/validation_tests/split.https.any.js b/tests/wpt/tests/webnn/validation_tests/split.https.any.js
index 6f7809744a7..91d00b0a6d7 100644
--- a/tests/wpt/tests/webnn/validation_tests/split.https.any.js
+++ b/tests/wpt/tests/webnn/validation_tests/split.https.any.js
@@ -52,9 +52,17 @@ const tests = [
     input: {dataType: 'float32', dimensions: [2, 6]},
     splits: [0],
     options: {
-      axis: 2,
+      axis: 0,
     }
   },
+  {
+    name: '[split] Throw if splits (scalar) is equal to 0.',
+    input: {dataType: 'float32', dimensions: [2, 6]},
+    splits: 0,
+    options: {
+      axis: 0,
+    },
+  },
   {
     name:
         '[split] Throw if the splits can not evenly divide the dimension size of input along options.axis.',
@@ -64,6 +72,15 @@ const tests = [
       axis: 1,
     }
   },
+  {
+    name:
+        '[split] Throw if splits (scalar) can not evenly divide the dimension size of input along options.axis.',
+    input: {dataType: 'float32', dimensions: [2, 5]},
+    splits: 2,
+    options: {
+      axis: 1,
+    },
+  },
   {
     name:
         '[split] Throw if the sum of splits sizes not equal to the dimension size of input along options.axis.',
diff --git a/tests/wpt/tests/webnn/validation_tests/where.https.any.js b/tests/wpt/tests/webnn/validation_tests/where.https.any.js
index a26fa249315..33394f86322 100644
--- a/tests/wpt/tests/webnn/validation_tests/where.https.any.js
+++ b/tests/wpt/tests/webnn/validation_tests/where.https.any.js
@@ -15,86 +15,103 @@ const kExampleInputDescriptor = {
 
 const tests = [
   {
-    name:
-        '[where] Throw if the condition data type is not uint8.',
+    name: '[where] Throw if the condition data type is not uint8.',
     condition: {dataType: 'float32', dimensions: [2, 4]},
-    input: {dataType: 'float32', dimensions: [2, 4]},
-    other: {dataType: 'float32', dimensions: [2, 4]},
+    trueValue: {dataType: 'float32', dimensions: [2, 4]},
+    falseValue: {dataType: 'float32', dimensions: [2, 4]},
   },
   {
     name:
-        '[where] Throw if the data types of input and other do not match',
+        '[where] Throw if the data types of trueValue and falseValue do not match',
     condition: {dataType: 'uint8', dimensions: [2, 4]},
-    input: {dataType: 'float16', dimensions: [2, 4]},
-    other: {dataType: 'float32', dimensions: [2, 4]},
+    trueValue: {dataType: 'float16', dimensions: [2, 4]},
+    falseValue: {dataType: 'float32', dimensions: [2, 4]},
   },
   {
     name:
-        '[where] Throw if the shapes of input and other are not broadcastable',
+        '[where] Throw if the shapes of trueValue and falseValue are not broadcastable',
     condition: {dataType: 'uint8', dimensions: [2, 4]},
-    input: {dataType: 'float32', dimensions: [2, 4]},
-    other: {dataType: 'float32', dimensions: [2, 3]},
+    trueValue: {dataType: 'float32', dimensions: [2, 4]},
+    falseValue: {dataType: 'float32', dimensions: [2, 3]},
   },
   {
-    name:
-        '[where] Throw if the condition shape is not broadcastable',
+    name: '[where] Throw if the condition shape is not broadcastable',
     condition: {dataType: 'uint8', dimensions: [2, 4]},
-    input: {dataType: 'float32', dimensions: [2, 3]},
-    other: {dataType: 'float32', dimensions: [2, 1]},
+    trueValue: {dataType: 'float32', dimensions: [2, 3]},
+    falseValue: {dataType: 'float32', dimensions: [2, 1]},
   },
   {
     name:
-        '[where] Test building where with 2-D condition, 2-D input and 2-D other using broadcast',
+        '[where] Test building where with 2-D condition, 2-D trueValue and 2-D falseValue using broadcast',
     condition: {dataType: 'uint8', dimensions: [2, 1]},
-    input: {dataType: 'float32', dimensions: [2, 4]},
-    other: {dataType: 'float32', dimensions: [2, 4]},
+    trueValue: {dataType: 'float32', dimensions: [2, 4]},
+    falseValue: {dataType: 'float32', dimensions: [2, 4]},
     output: {dataType: 'float32', dimensions: [2, 4]},
   },
   {
     name:
-        '[where] Test building where with 2-D condition, 2-D input and 3-D other using broadcast',
+        '[where] Test building where with 2-D condition, 2-D trueValue and 3-D falseValue using broadcast',
     condition: {dataType: 'uint8', dimensions: [1, 4]},
-    input: {dataType: 'float32', dimensions: [3, 4]},
-    other: {dataType: 'float32', dimensions: [2, 3, 4]},
-    output: {dataType: 'float32', dimensions: [2, 3, 4]},
+    trueValue: {dataType: 'float16', dimensions: [3, 4]},
+    falseValue: {dataType: 'float16', dimensions: [2, 3, 4]},
+    output: {dataType: 'float16', dimensions: [2, 3, 4]},
   },
   {
     name:
-        '[where] Test building where with 3-D condition, 3-D input and 2-D other using broadcast',
+        '[where] Test building where with 3-D condition, 3-D trueValue and 2-D falseValue using broadcast',
     condition: {dataType: 'uint8', dimensions: [2, 1, 4]},
-    input: {dataType: 'float32', dimensions: [2, 3, 4]},
-    other: {dataType: 'float32', dimensions: [1, 4]},
-    output: {dataType: 'float32', dimensions: [2, 3, 4]},
+    trueValue: {dataType: 'int32', dimensions: [2, 3, 4]},
+    falseValue: {dataType: 'int32', dimensions: [1, 4]},
+    output: {dataType: 'int32', dimensions: [2, 3, 4]},
   },
   {
     name:
-        '[where] Test building where with 4-D condition, 3-D input and 2-D other using broadcast',
+        '[where] Test building where with 4-D condition, 3-D trueValue and 2-D falseValue using broadcast',
     condition: {dataType: 'uint8', dimensions: [2, 3, 4, 5]},
-    input: {dataType: 'float32', dimensions: [3, 4, 5]},
-    other: {dataType: 'float32', dimensions: [4, 5]},
-    output: {dataType: 'float32', dimensions: [2, 3, 4, 5]},
+    trueValue: {dataType: 'uint32', dimensions: [3, 4, 5]},
+    falseValue: {dataType: 'uint32', dimensions: [4, 5]},
+    output: {dataType: 'uint32', dimensions: [2, 3, 4, 5]},
   }
 ];
 
 tests.forEach(
     test => promise_test(async t => {
+      for (let operand of [test.condition, test.trueValue, test.falseValue]) {
+        if (!context.opSupportLimits().input.dataTypes.includes(
+                operand.dataType)) {
+          assert_throws_js(TypeError, () => builder.input('input', {
+            dataType: operand.dataType,
+            dimensions: operand.dimensions
+          }));
+          return;
+        }
+      }
+
       const condition = builder.input('condition', {
         dataType: test.condition.dataType,
         dimensions: test.condition.dimensions
       });
-      const input = builder.input(
-          'input',
-          {dataType: test.input.dataType, dimensions: test.input.dimensions});
-      const other = builder.input(
-          'other',
-          {dataType: test.other.dataType, dimensions: test.other.dimensions});
-      if (test.output) {
-        const output = builder.where(condition, input, other);
+      const trueValue = builder.input('trueValue', {
+        dataType: test.trueValue.dataType,
+        dimensions: test.trueValue.dimensions
+      });
+      const falseValue = builder.input('falseValue', {
+        dataType: test.falseValue.dataType,
+        dimensions: test.falseValue.dimensions
+      });
+      if (test.output &&
+          context.opSupportLimits().where.condition.dataTypes.includes(
+              test.condition.dataType) &&
+          context.opSupportLimits().where.trueValue.dataTypes.includes(
+              test.trueValue.dataType) &&
+          context.opSupportLimits().where.falseValue.dataTypes.includes(
+              test.falseValue.dataType)) {
+        const output = builder.where(condition, trueValue, falseValue);
         assert_equals(output.dataType(), test.output.dataType);
         assert_array_equals(output.shape(), test.output.dimensions);
       } else {
         assert_throws_js(
-            TypeError, () => builder.where(condition, input, other));
+            TypeError, () => builder.where(condition, trueValue, falseValue));
       }
     }, test.name));
 
@@ -102,28 +119,31 @@ multi_builder_test(async (t, builder, otherBuilder) => {
   const conditionFromOtherBuilder =
       otherBuilder.input('condition', kExampleConditionDescriptor);
 
-  const input = builder.input('input', kExampleInputDescriptor);
-  const other = builder.input('other', kExampleInputDescriptor);
+  const trueValue = builder.input('trueValue', kExampleInputDescriptor);
+  const falseValue = builder.input('falseValue', kExampleInputDescriptor);
   assert_throws_js(
-      TypeError, () => builder.where(conditionFromOtherBuilder, input, other));
+      TypeError,
+      () => builder.where(conditionFromOtherBuilder, trueValue, falseValue));
 }, '[where] throw if condition is from another builder');
 
 multi_builder_test(async (t, builder, otherBuilder) => {
-  const inputFromOtherBuilder =
-      otherBuilder.input('input', kExampleInputDescriptor);
+  const trueValueFromOtherBuilder =
+      otherBuilder.input('trueValue', kExampleInputDescriptor);
 
   const condition = builder.input('condition', kExampleConditionDescriptor);
-  const other = builder.input('other', kExampleInputDescriptor);
+  const falseValue = builder.input('falseValue', kExampleInputDescriptor);
   assert_throws_js(
-      TypeError, () => builder.where(condition, inputFromOtherBuilder, other));
-}, '[where] throw if input is from another builder');
+      TypeError,
+      () => builder.where(condition, trueValueFromOtherBuilder, falseValue));
+}, '[where] throw if trueValue is from another builder');
 
 multi_builder_test(async (t, builder, otherBuilder) => {
-  const otherFromOtherBuilder =
-      otherBuilder.input('other', kExampleInputDescriptor);
+  const falseValueFromOtherBuilder =
+      otherBuilder.input('falseValue', kExampleInputDescriptor);
 
   const condition = builder.input('condition', kExampleConditionDescriptor);
-  const input = builder.input('input', kExampleInputDescriptor);
+  const trueValue = builder.input('trueValue', kExampleInputDescriptor);
   assert_throws_js(
-      TypeError, () => builder.where(condition, input, otherFromOtherBuilder));
-}, '[where] throw if other is from another builder');
+      TypeError,
+      () => builder.where(condition, trueValue, falseValueFromOtherBuilder));
+}, '[where] throw if falseValue is from another builder');