dom: Convert parent dictionary values when converting dictionaries to JS.

components/script/dom/bindings/codegen/CodegenRust.py

@@ -6557,7 +6557,10 @@ class CGDictionary(CGThing):
                                       (name, name, varInsert(name, member.identifier.name).define()))
             return CGGeneric("%s\n" % insertion.define())
 
-        memberInserts = CGList([memberInsert(m) for m in self.memberInfo])
+        memberInserts = [memberInsert(m) for m in self.memberInfo]
+
+        if d.parent:
+            memberInserts = [CGGeneric("self.parent.to_jsobject(cx, obj);\n")] + memberInserts
 
         selfName = self.makeClassName(d)
         if self.membersNeedTracing():
@@ -6602,10 +6605,16 @@ class CGDictionary(CGThing):
             "    }\n"
             "}\n"
             "\n"
+            "impl ${selfName} {\n"
+            "    pub(crate) unsafe fn to_jsobject(&self, cx: *mut JSContext, mut obj: MutableHandleObject) {\n"
+            "${insertMembers}"
+            "    }\n"
+            "}\n"
+            "\n"
             "impl ToJSValConvertible for ${selfName} {\n"
             "    unsafe fn to_jsval(&self, cx: *mut JSContext, mut rval: MutableHandleValue) {\n"
-            "        rooted!(in(cx) let obj = JS_NewObject(cx, ptr::null()));\n"
+            "        rooted!(in(cx) let mut obj = JS_NewObject(cx, ptr::null()));\n"
-            "${insertMembers}"
+            "        self.to_jsobject(cx, obj.handle_mut());\n"
             "        rval.set(ObjectOrNullValue(obj.get()))\n"
             "    }\n"
             "}\n").substitute({
@@ -6614,7 +6623,7 @@ class CGDictionary(CGThing):
                 "empty": CGIndenter(CGGeneric(self.makeEmpty()), indentLevel=4).define(),
                 "initParent": CGIndenter(CGGeneric(initParent), indentLevel=16).define(),
                 "initMembers": CGIndenter(memberInits, indentLevel=16).define(),
-                "insertMembers": CGIndenter(memberInserts, indentLevel=8).define(),
+                "insertMembers": CGIndenter(CGList(memberInserts), indentLevel=8).define(),
                 "preInitial": CGIndenter(CGGeneric(preInitial), indentLevel=8).define(),
                 "postInitial": CGIndenter(CGGeneric(postInitial), indentLevel=8).define(),
             })

components/script/dom/testbinding.rs

@@ -8,6 +8,8 @@ use crate::dom::bindings::callback::ExceptionHandling;
 use crate::dom::bindings::codegen::Bindings::EventListenerBinding::EventListener;
 use crate::dom::bindings::codegen::Bindings::FunctionBinding::Function;
 use crate::dom::bindings::codegen::Bindings::TestBindingBinding::SimpleCallback;
+use crate::dom::bindings::codegen::Bindings::TestBindingBinding::TestDictionaryParent;
+use crate::dom::bindings::codegen::Bindings::TestBindingBinding::TestDictionaryWithParent;
 use crate::dom::bindings::codegen::Bindings::TestBindingBinding::{
     TestBindingMethods, TestDictionary,
 };
@@ -1079,6 +1081,15 @@ impl TestBindingMethods for TestBinding {
     fn SemiExposedBoolFromPartialInterface(&self) -> bool {
         true
     }
+
+    fn GetDictionaryWithParent(&self, s1: DOMString, s2: DOMString) -> TestDictionaryWithParent {
+        TestDictionaryWithParent {
+            parent: TestDictionaryParent {
+                parentStringMember: Some(s1),
+            },
+            stringMember: Some(s2),
+        }
+    }
 }
 
 #[allow(non_snake_case)]

components/script/dom/webidls/TestBinding.webidl

@@ -45,6 +45,14 @@ dictionary TestDictionary {
   DOMString? nonRequiredNullable2;
 };
 
+dictionary TestDictionaryParent {
+  DOMString parentStringMember;
+};
+
+dictionary TestDictionaryWithParent : TestDictionaryParent {
+  DOMString stringMember;
+};
+
 dictionary TestDictionaryDefaults {
   boolean booleanValue = false;
   byte byteValue = 7;
@@ -571,6 +579,8 @@ interface TestBinding {
 
   [Exposed=(Window)]
   readonly attribute boolean semiExposedBoolFromInterface;
+
+  TestDictionaryWithParent getDictionaryWithParent(DOMString parent, DOMString child);
 };
 
 [Exposed=(Window)]

tests/wpt/mozilla/meta-layout-2020/mozilla/dictionary_to_jsval.html.ini

@@ -0,0 +1,2 @@
+[dictionary_to_jsval.html]
+  prefs: [dom.testbinding.enabled:true]

tests/wpt/mozilla/meta/MANIFEST.json

@@ -13357,6 +13357,13 @@
       {}
      ]
     ],
+    "dictionary_to_jsval.html": [
+     "e31a7e5cfaa0635d41ab2adac96318b574c58a10",
+     [
+      null,
+      {}
+     ]
+    ],
     "documentElement.html": [
      "aee3278ba84ca12a77286a1c03dbaec9fc3a7cd0",
      [

tests/wpt/mozilla/meta/mozilla/dictionary_to_jsval.html.ini

@@ -0,0 +1,2 @@
+[dictionary_to_jsval.html]
+  prefs: [dom.testbinding.enabled:true]

tests/wpt/mozilla/tests/mozilla/dictionary_to_jsval.html

@@ -0,0 +1,12 @@
+<html>
+<head>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+  test(function() {
+      let b = new TestBinding();
+      let dict = b.getDictionaryWithParent("parent", "child");
+      assert_equals(dict.parentStringMember, "parent");
+      assert_equals(dict.stringMember, "child");
+  });
+</script>