Bug 1969004 - CSS Highlight API: Make Highlight.add() and HighlightRegistry.set() chainable. a=dmeehan

Original Revision: https://phabricator.services.mozilla.com/D251599

Differential Revision: https://phabricator.services.mozilla.com/D252466

dom/base/Highlight.cpp

@@ -125,7 +125,7 @@ void Highlight::SetType(HighlightType aHighlightType) {
   Repaint();
 }
 
-void Highlight::Add(AbstractRange& aRange, ErrorResult& aRv) {
+Highlight* Highlight::Add(AbstractRange& aRange, ErrorResult& aRv) {
   // Manually check if the range `aKey` is already present in this highlight,
   // because `SetlikeHelpers::Add()` doesn't indicate this.
   // To keep the setlike and the mirrored array in sync, the range must not
@@ -134,11 +134,11 @@ void Highlight::Add(AbstractRange& aRange, ErrorResult& aRv) {
   // `nsTArray<>::Contains()`.
   if (Highlight_Binding::SetlikeHelpers::Has(this, aRange, aRv) ||
       aRv.Failed()) {
-    return;
+    return this;
   }
   Highlight_Binding::SetlikeHelpers::Add(this, aRange, aRv);
   if (aRv.Failed()) {
-    return;
+    return this;
   }
 
   MOZ_ASSERT(!mRanges.Contains(&aRange),
@@ -155,9 +155,10 @@ void Highlight::Add(AbstractRange& aRange, ErrorResult& aRv) {
     // no strong reference is needed to keep `registry` alive.
     MOZ_KnownLive(registry)->MaybeAddRangeToHighlightSelection(aRange, *this);
     if (aRv.Failed()) {
-      return;
+      return this;
     }
   }
+  return this;
 }
 
 void Highlight::Clear(ErrorResult& aRv) {

dom/base/Highlight.h

@@ -144,7 +144,8 @@ class Highlight final : public nsISupports, public nsWrapperCache {
    *
    * Also notifies all `HighlightRegistry` instances.
    */
-  MOZ_CAN_RUN_SCRIPT void Add(AbstractRange& aRange, ErrorResult& aRv);
+  MOZ_CAN_RUN_SCRIPT Highlight* Add(AbstractRange& aRange,
+                                           ErrorResult& aRv);
 
   /**
    * @brief Removes all ranges from this highlight.

dom/base/HighlightRegistry.cpp

@@ -146,18 +146,18 @@ void HighlightRegistry::AddHighlightSelectionsToFrameSelection() {
   }
 }
 
-void HighlightRegistry::Set(const nsAString& aKey, Highlight& aValue,
-                            ErrorResult& aRv) {
+HighlightRegistry* HighlightRegistry::Set(const nsAString& aKey,
+                                          Highlight& aValue, ErrorResult& aRv) {
   // manually check if the highlight `aKey` is already registered to be able to
   // provide a fast path later that avoids calling `std::find_if()`.
   const bool highlightAlreadyPresent =
       HighlightRegistry_Binding::MaplikeHelpers::Has(this, aKey, aRv);
   if (aRv.Failed()) {
-    return;
+    return this;
   }
   HighlightRegistry_Binding::MaplikeHelpers::Set(this, aKey, aValue, aRv);
   if (aRv.Failed()) {
-    return;
+    return this;
   }
   RefPtr<nsFrameSelection> frameSelection = GetFrameSelection();
   RefPtr<nsAtom> highlightNameAtom = NS_AtomizeMainThread(aKey);
@@ -184,6 +184,7 @@ void HighlightRegistry::Set(const nsAString& aKey, Highlight& aValue,
   if (frameSelection) {
     frameSelection->AddHighlightSelection(highlightNameAtom, aValue);
   }
+  return this;
 }
 
 void HighlightRegistry::Clear(ErrorResult& aRv) {

dom/base/HighlightRegistry.h

@@ -109,8 +109,9 @@ class HighlightRegistry final : public nsISupports, public nsWrapperCache {
    *
    * If a `FrameSelection` is present, a highlight selection is created.
    */
-  MOZ_CAN_RUN_SCRIPT void Set(const nsAString& aKey, Highlight& aValue,
-                              ErrorResult& aRv);
+  MOZ_CAN_RUN_SCRIPT HighlightRegistry* Set(const nsAString& aKey,
+                                            Highlight& aValue,
+                                            ErrorResult& aRv);
 
   /**
    * @brief Removes all highlights from this registry.

dom/webidl/Highlight.webidl

@@ -41,7 +41,7 @@ partial interface Highlight {
   // Iterating a setlike is not possible from C++ yet.
   // Therefore a separate data structure must be held and kept in sync.
   [Throws]
-  undefined add(AbstractRange range);
+  Highlight add(AbstractRange range);
   [Throws]
   undefined clear();
   [Throws]
@@ -63,7 +63,7 @@ partial interface HighlightRegistry {
   // Iterating a maplike is not possible from C++ yet.
   // Therefore, a separate data structure must be held and kept in sync.
   [Throws]
-  undefined set(DOMString key, Highlight value);
+  HighlightRegistry set(DOMString key, Highlight value);
   [Throws]
   undefined clear();
   [Throws]

testing/web-platform/tests/css/css-highlight-api/Highlight-setlike.html

@@ -61,6 +61,15 @@
       assert_equals(customHighlight.size, 2, 'Highlight.size is 2 after only adding two different ranges');
     }, 'Highlight add and has methods work as expected' + rangesCombinationDescription);
 
+    test(() => {
+      let customHighlight = new Highlight();
+      customHighlight.add(rangeCollections[i][0]).add(rangeCollections[i][1]);
+      assert_true(customHighlight.has(rangeCollections[i][0]), 'Highlight.has returns true when it contains the first range added');
+      assert_true(customHighlight.has(rangeCollections[i][1]), 'Highlight.has returns true when it contains the second range added');
+      assert_false(customHighlight.has(rangeCollections[i][2]), 'Highlight.has returns false when it doesn\'t contain the range which is passed as the argument');
+      assert_equals(customHighlight.size, 2, 'Highlight.size is 2 after adding two different ranges by chaining the add method');
+    }, "Highlight add method is chainable" + rangesCombinationDescription);
+
     test(() => {
       let customHighlight = new Highlight(rangeCollections[i][0], rangeCollections[i][1]);
       assert_false(customHighlight.delete(rangeCollections[i][2]), 'Highlight.delete returns false when trying to delete a range that is not in the highlight');

testing/web-platform/tests/css/css-highlight-api/HighlightRegistry-maplike.html

@@ -70,6 +70,9 @@
     assert_equals(CSS.highlights.size, 0, 'HighlightRegistry.clear empties the map.');
     CSS.highlights.clear();
     assert_equals(CSS.highlights.size, 0, 'HighlightRegistry.clear called with an empty registry keeps it empty.');
+
+    CSS.highlights.set(name1, h1).set(name2, h2);
+    assert_equals(CSS.highlights.size, 2, 'HighlightRegistry.size is 2 after inserting two different Highlights by chaining the set method.');
   }, 'HighlightRegistry has a maplike interface.');
 
 </script>