Auto merge of #19946 - paavininanda:Issue18613, r=jdm

Change Offset_to_text_point function and add unit tests

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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #18613.

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- [x] Added unit tests and web platform tests

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components/script/textinput.rs

@@ -871,13 +871,12 @@ impl<T: ClipboardProvider> TextInput<T> {
     fn offset_to_text_point(&self, abs_point: usize) -> TextPoint {
         let mut index = abs_point;
         let mut line = 0;
-
         let last_line_idx = self.lines.len() - 1;
         self.lines.iter().enumerate().fold(0, |acc, (i, val)| {
             if i != last_line_idx {
-                let line_end = max(val.len(), 1);
-                let new_acc = acc + line_end;
-                if abs_point > new_acc && index > line_end {
+                let line_end = val.len();
+                let new_acc = acc + line_end + 1;
+                if abs_point >= new_acc && index > line_end {
                     index -= line_end + 1;
                     line += 1;
                 }

tests/unit/script/textinput.rs

@@ -600,6 +600,27 @@ fn test_textinput_set_selection_with_direction() {
     assert!(textinput.selection_origin.is_some());
     assert_eq!(textinput.selection_origin.unwrap().line, 0);
     assert_eq!(textinput.selection_origin.unwrap().index, 6);
+
+    textinput = text_input(Lines::Multiple, "\n\n");
+    textinput.set_selection_range(0, 1, SelectionDirection::Forward);
+    assert_eq!(textinput.edit_point.line, 1);
+    assert_eq!(textinput.edit_point.index, 0);
+    assert_eq!(textinput.selection_direction, SelectionDirection::Forward);
+
+    assert!(textinput.selection_origin.is_some());
+    assert_eq!(textinput.selection_origin.unwrap().line, 0);
+    assert_eq!(textinput.selection_origin.unwrap().index, 0);
+
+    textinput = text_input(Lines::Multiple, "\n");
+    textinput.set_selection_range(0, 1, SelectionDirection::Forward);
+    assert_eq!(textinput.edit_point.line, 1);
+    assert_eq!(textinput.edit_point.index, 0);
+    assert_eq!(textinput.selection_direction, SelectionDirection::Forward);
+
+    assert!(textinput.selection_origin.is_some());
+    assert_eq!(textinput.selection_origin.unwrap().line, 0);
+    assert_eq!(textinput.selection_origin.unwrap().index, 0);
+
 }
 
 #[test]
@@ -629,4 +650,11 @@ fn test_selection_bounds() {
     assert_eq!(TextPoint { line: 0, index: 6 }, textinput.selection_end());
     assert_eq!(3, textinput.selection_start_offset());
     assert_eq!(6, textinput.selection_end_offset());
+
+    textinput = text_input(Lines::Multiple, "\n\n");
+    textinput.set_selection_range(0, 1, SelectionDirection::Forward);
+    assert_eq!(TextPoint { line: 0, index: 0 }, textinput.selection_origin_or_edit_point());
+    assert_eq!(TextPoint { line: 0, index: 0 }, textinput.selection_start());
+    assert_eq!(TextPoint { line: 1, index: 0 }, textinput.selection_end());
+
 }

tests/wpt/metadata/MANIFEST.json

@@ -354355,6 +354355,12 @@
      {}
     ]
    ],
+   "selection/setSelectionRange.html": [
+    [
+     "/selection/setSelectionRange.html",
+     {}
+    ]
+   ],
    "selection/type.html": [
     [
      "/selection/type.html",
@@ -582154,6 +582160,10 @@
    "856ba9771d2c1e2eaae00dcf6b8378a42003cc7a",
    "testharness"
   ],
+  "selection/setSelectionRange.html": [
+   "a047ea5e4c00894fcc30e972f84bcedc4a8226cf",
+   "testharness"
+  ],
   "selection/test-iframe.html": [
    "3803c785b4a2fe2bbf9ecb895e6d3e1ae9e40164",
    "support"

tests/wpt/metadata/selection/setSelectionRange.html.ini

@@ -0,0 +1,4 @@
+[setSelectionRange.html]
+  type: testharness
+  [setSelectionRange on line boundaries]
+    expected: FAIL

tests/wpt/web-platform-tests/selection/setSelectionRange.html

@@ -0,0 +1,18 @@
+<!doctype html>
+<meta charset="utf-8">
+<title></title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<textarea>
+
+</textarea>
+<script>
+test(function() {
+    let textarea = document.querySelector('textarea');
+    assert_equals(textarea.selectionStart, 0);
+    assert_equals(textarea.selectionEnd, 0);
+    textarea.setSelectionRange(0, 1);
+    assert_equals(textarea.selectionStart, 0);
+    assert_equals(textarea.selectionEnd, 1);
+}, "setSelectionRange on line boundaries");
+</script>