Bug 1626015 - Implement ParentNode#ReplaceChildren. r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D75891

Author: ajvincent

Diff for: dom/base/nsINode.cpp

@@ -2025,6 +2025,35 @@ void nsINode::Append(const Sequence<OwningNodeOrString>& aNodes,
   AppendChild(*node, aRv);
 }
 
+// https://dom.spec.whatwg.org/#dom-parentnode-replacechildren
+void nsINode::ReplaceChildren(const Sequence<OwningNodeOrString>& aNodes,
+                              ErrorResult& aRv) {
+  nsCOMPtr<Document> doc = OwnerDoc();
+  nsCOMPtr<nsINode> node = ConvertNodesOrStringsIntoNode(aNodes, doc, aRv);
+  if (aRv.Failed()) {
+    return;
+  }
+
+  EnsurePreInsertionValidity(*node, nullptr, aRv);
+  if (aRv.Failed()) {
+    return;
+  }
+
+  // Needed when used in combination with contenteditable (maybe)
+  mozAutoDocUpdate updateBatch(doc, true);
+
+  nsAutoMutationBatch mb(this, true, false);
+
+  // Replace all with node within this.
+  while (mFirstChild) {
+    RemoveChildNode(mFirstChild, true);
+  }
+  mb.RemovalDone();
+
+  AppendChild(*node, aRv);
+  mb.NodesAdded();
+}
+
 void nsINode::RemoveChildNode(nsIContent* aKid, bool aNotify) {
   // NOTE: This function must not trigger any calls to
   // Document::GetRootElement() calls until *after* it has removed aKid from

Diff for: dom/base/nsINode.h

@@ -2033,6 +2033,8 @@ class nsINode : public mozilla::dom::EventTarget {
                                   ErrorResult& aRv);
   MOZ_CAN_RUN_SCRIPT void Append(const Sequence<OwningNodeOrString>& aNodes,
                                  ErrorResult& aRv);
+  MOZ_CAN_RUN_SCRIPT void ReplaceChildren(
+      const Sequence<OwningNodeOrString>& aNodes, ErrorResult& aRv);
 
   void GetBoxQuads(const BoxQuadOptions& aOptions,
                    nsTArray<RefPtr<DOMQuad>>& aResult, CallerType aCallerType,

Diff for: dom/webidl/ParentNode.webidl

@@ -28,4 +28,6 @@ interface mixin ParentNode {
   void prepend((Node or DOMString)... nodes);
   [CEReactions, Throws, Unscopable]
   void append((Node or DOMString)... nodes);
+  [CEReactions, Throws, Unscopable]
+  void replaceChildren((Node or DOMString)... nodes);
 };

Diff for: testing/web-platform/meta/dom/idlharness.window.js.ini

@@ -6,37 +6,3 @@
 
   [ShadowRoot interface: attribute onslotchange]
     expected: FAIL
-
-  [Element interface: element must inherit property "replaceChildren((Node or DOMString)...)" with the proper type]
-    expected: FAIL
-
-  [Document interface: calling replaceChildren((Node or DOMString)...) on xmlDoc with too few arguments must throw TypeError]
-    expected: FAIL
-
-  [Document interface: calling replaceChildren((Node or DOMString)...) on new Document() with too few arguments must throw TypeError]
-    expected: FAIL
-
-  [DocumentFragment interface: document.createDocumentFragment() must inherit property "replaceChildren((Node or DOMString)...)" with the proper type]
-    expected: FAIL
-
-  [DocumentFragment interface: operation replaceChildren((Node or DOMString)...)]
-    expected: FAIL
-
-  [Element interface: operation replaceChildren((Node or DOMString)...)]
-    expected: FAIL
-
-  [Document interface: operation replaceChildren((Node or DOMString)...)]
-    expected: FAIL
-
-  [Element interface: calling replaceChildren((Node or DOMString)...) on element with too few arguments must throw TypeError]
-    expected: FAIL
-
-  [Document interface: new Document() must inherit property "replaceChildren((Node or DOMString)...)" with the proper type]
-    expected: FAIL
-
-  [DocumentFragment interface: calling replaceChildren((Node or DOMString)...) on document.createDocumentFragment() with too few arguments must throw TypeError]
-    expected: FAIL
-
-  [Document interface: xmlDoc must inherit property "replaceChildren((Node or DOMString)...)" with the proper type]
-    expected: FAIL
-

Diff for: testing/web-platform/meta/dom/nodes/ParentNode-replaceChildren.html.ini

@@ -94,14 +94,14 @@
 
       const observer = new MutationObserver(mutations => {
         t.step(() => {
-          assert_equals(phase, 1);
-          assert_equals(mutations.length, 1);
+          assert_equals(phase, 1, "phase");
+          assert_equals(mutations.length, 1, "mutations.length");
           const mutation = mutations[0];
-          assert_equals(mutation.type, "childList");
-          assert_equals(mutation.addedNodes.length, 2);
-          assert_array_equals([...mutation.addedNodes], insertions);
-          assert_equals(mutation.removedNodes.length, 2);
-          assert_array_equals([...mutation.removedNodes], children);
+          assert_equals(mutation.type, "childList", "mutation.type");
+          assert_equals(mutation.addedNodes.length, 2, "added nodes length");
+          assert_array_equals([...mutation.addedNodes], insertions, "added nodes");
+          assert_equals(mutation.removedNodes.length, 2, "removed nodes length");
+          assert_array_equals([...mutation.removedNodes], children, "removed nodes");
         });
         t.done();
       });