Add isUnique option in RawEvent and refactor EventQueue to use it (#50987)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/50987

Changelog: [internal]

This adds a new `isUnique` option in `RawEvent` to determine if it's unique (whether it should be coalesced with other unique events of the same type and target).

This effectively makes `dispatchUniqueEvent` redundant, as we can use `dispatchEvent` with a `RawEvent` marked as unique.

This will allow us to fix the bug we found in the new tests for event dispatching, where non-unique events of a given type where being coalesced with non-unique events of the same type.

Reviewed By: javache

Differential Revision: D73849220

fbshipit-source-id: ce89623aee509071ab6a86654ee25d9614863a8a

packages/react-native/ReactCommon/react/renderer/core/EventQueue.cpp

@@ -29,40 +29,40 @@ EventQueue::EventQueue(
 void EventQueue::enqueueEvent(RawEvent&& rawEvent) const {
   {
     std::scoped_lock lock(queueMutex_);
-    eventQueue_.push_back(std::move(rawEvent));
+
+    if (rawEvent.isUnique) {
+      auto repeatedEvent = eventQueue_.rend();
+
+      for (auto it = eventQueue_.rbegin(); it != eventQueue_.rend(); ++it) {
+        if (it->type == rawEvent.type &&
+            it->eventTarget == rawEvent.eventTarget) {
+          repeatedEvent = it;
+          break;
+        } else if (it->eventTarget == rawEvent.eventTarget) {
+          // It is necessary to maintain order of different event types
+          // for the same target. If the same target has event types A1, B1
+          // in the event queue and event A2 occurs. A1 has to stay in the
+          // queue.
+          break;
+        }
+      }
+
+      if (repeatedEvent == eventQueue_.rend()) {
+        eventQueue_.push_back(std::move(rawEvent));
+      } else {
+        *repeatedEvent = std::move(rawEvent);
+      }
+    } else {
+      eventQueue_.push_back(std::move(rawEvent));
+    }
   }
 
   onEnqueue();
 }
 
 void EventQueue::enqueueUniqueEvent(RawEvent&& rawEvent) const {
-  {
-    std::scoped_lock lock(queueMutex_);
-
-    auto repeatedEvent = eventQueue_.rend();
-
-    for (auto it = eventQueue_.rbegin(); it != eventQueue_.rend(); ++it) {
-      if (it->type == rawEvent.type &&
-          it->eventTarget == rawEvent.eventTarget) {
-        repeatedEvent = it;
-        break;
-      } else if (it->eventTarget == rawEvent.eventTarget) {
-        // It is necessary to maintain order of different event types
-        // for the same target. If the same target has event types A1, B1
-        // in the event queue and event A2 occurs. A1 has to stay in the
-        // queue.
-        break;
-      }
-    }
-
-    if (repeatedEvent == eventQueue_.rend()) {
-      eventQueue_.push_back(std::move(rawEvent));
-    } else {
-      *repeatedEvent = std::move(rawEvent);
-    }
-  }
-
-  onEnqueue();
+  rawEvent.isUnique = true;
+  enqueueEvent(std::move(rawEvent));
 }
 
 void EventQueue::enqueueStateUpdate(StateUpdate&& stateUpdate) const {

packages/react-native/ReactCommon/react/renderer/core/RawEvent.cpp

@@ -13,10 +13,12 @@ RawEvent::RawEvent(
     std::string type,
     SharedEventPayload eventPayload,
     SharedEventTarget eventTarget,
-    Category category)
+    Category category,
+    bool isUnique)
     : type(std::move(type)),
       eventPayload(std::move(eventPayload)),
       eventTarget(std::move(eventTarget)),
-      category(category) {}
+      category(category),
+      isUnique(isUnique) {}
 
 } // namespace facebook::react

packages/react-native/ReactCommon/react/renderer/core/RawEvent.h

@@ -69,13 +69,15 @@ struct RawEvent {
       std::string type,
       SharedEventPayload eventPayload,
       SharedEventTarget eventTarget,
-      Category category = Category::Unspecified);
+      Category category = Category::Unspecified,
+      bool isUnique = false);
 
   std::string type;
   SharedEventPayload eventPayload;
   SharedEventTarget eventTarget;
   Category category;
   EventTag loggingTag{0};
+  bool isUnique{false};
 
   // The client may specify a platform-specific timestamp for the event start
   // time, for example when MotionEvent was triggered on the Android native