Add tests for performance.eventCounts (#52463)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/52463

Changelog: [internal]

This adds Fantom tests for `performance.eventCounts`.

Reviewed By: huntie

Differential Revision: D77860881

fbshipit-source-id: 26b9ef56b9c610cbad7011bc0adde27251fda909

packages/react-native/ReactCommon/react/nativemodule/webperformance/NativePerformance.cpp

@@ -464,4 +464,8 @@ void NativePerformance::setCurrentTimeStampForTesting(
   forcedCurrentTimeStamp_ = ts;
 }
 
+void NativePerformance::clearEventCountsForTesting(jsi::Runtime& /*rt*/) {
+  PerformanceEntryReporter::getInstance()->clearEventCounts();
+}
+
 } // namespace facebook::react

packages/react-native/ReactCommon/react/nativemodule/webperformance/NativePerformance.h

@@ -199,6 +199,7 @@ class NativePerformance : public NativePerformanceCxxSpec<NativePerformance> {
 #pragma mark - Testing
 
   void setCurrentTimeStampForTesting(jsi::Runtime& rt, HighResTimeStamp ts);
+  void clearEventCountsForTesting(jsi::Runtime& rt);
 
  private:
   std::optional<HighResTimeStamp> forcedCurrentTimeStamp_;

packages/react-native/ReactCommon/react/performance/timeline/PerformanceEntryReporter.cpp

@@ -213,6 +213,10 @@ PerformanceMeasure PerformanceEntryReporter::reportMeasure(
   return entry;
 }
 
+void PerformanceEntryReporter::clearEventCounts() {
+  eventCounts_.clear();
+}
+
 std::optional<HighResTimeStamp> PerformanceEntryReporter::getMarkTime(
     const std::string& markName) const {
   std::shared_lock lock(buffersMutex_);

packages/react-native/ReactCommon/react/performance/timeline/PerformanceEntryReporter.h

@@ -81,6 +81,8 @@ class PerformanceEntryReporter {
     return eventCounts_;
   }
 
+  void clearEventCounts();
+
   std::optional<HighResTimeStamp> getMarkTime(
       const std::string& markName) const;
 

packages/react-native/src/private/webapis/performance/__tests__/EventTimingAPI-itest.js

@@ -10,8 +10,10 @@
 
 import '@react-native/fantom/src/setUpDefaultReactNativeEnvironment';
 
+import type Performance from 'react-native/src/private/webapis/performance/Performance';
 import type {PerformanceObserverEntryList} from 'react-native/src/private/webapis/performance/PerformanceObserver';
 
+import NativePerformance from '../specs/NativePerformance';
 import * as Fantom from '@react-native/fantom';
 import nullthrows from 'nullthrows';
 import {useState} from 'react';
@@ -22,6 +24,8 @@ import {PerformanceObserver} from 'react-native/src/private/webapis/performance/
 
 setUpPerformanceObserver();
 
+declare var performance: Performance;
+
 function sleep(ms: number) {
   const end = performance.now() + ms;
   while (performance.now() < end) {}
@@ -187,4 +191,61 @@ describe('Event Timing API', () => {
 
     expect(entry.interactionId).toBeGreaterThanOrEqual(0);
   });
+
+  it('reports number of dispatched events via performance.eventCounts', () => {
+    NativePerformance?.clearEventCountsForTesting?.();
+
+    const root = Fantom.createRoot();
+    Fantom.runTask(() => {
+      root.render(<View />);
+    });
+
+    const element = nullthrows(root.document.documentElement.firstElementChild);
+
+    expect(performance.eventCounts).not.toBeInstanceOf(Map);
+
+    // FIXME: this isn't spec compliant, as the map should be prepopulated with
+    // all the supported event names mapped to 0.
+    expect(performance.eventCounts.size).toBe(0);
+    expect([...performance.eventCounts.entries()]).toEqual([]);
+    const initialForEachCallback = jest.fn();
+    performance.eventCounts.forEach(initialForEachCallback);
+    expect(initialForEachCallback.mock.calls).toEqual([]);
+    expect([...performance.eventCounts.keys()]).toEqual([]);
+    expect([...performance.eventCounts.values()]).toEqual([]);
+
+    Fantom.dispatchNativeEvent(element, 'click');
+    Fantom.dispatchNativeEvent(element, 'click');
+    Fantom.dispatchNativeEvent(element, 'click');
+
+    Fantom.dispatchNativeEvent(element, 'pointerDown');
+    Fantom.dispatchNativeEvent(element, 'pointerUp');
+
+    expect(performance.eventCounts.size).toBe(3);
+    expect(performance.eventCounts.get('click')).toBe(3);
+    expect(performance.eventCounts.get('pointerdown')).toBe(1);
+    expect(performance.eventCounts.get('pointerup')).toBe(1);
+
+    expect([...performance.eventCounts.entries()]).toEqual([
+      ['pointerup', 1],
+      ['pointerdown', 1],
+      ['click', 3],
+    ]);
+
+    const forEachCallback = jest.fn();
+    performance.eventCounts.forEach(forEachCallback);
+    expect(forEachCallback.mock.calls).toEqual([
+      [1, 'pointerup', performance.eventCounts],
+      [1, 'pointerdown', performance.eventCounts],
+      [3, 'click', performance.eventCounts],
+    ]);
+
+    expect([...performance.eventCounts.keys()]).toEqual([
+      'pointerup',
+      'pointerdown',
+      'click',
+    ]);
+
+    expect([...performance.eventCounts.values()]).toEqual([1, 1, 3]);
+  });
 });

packages/react-native/src/private/webapis/performance/specs/NativePerformance.js

@@ -107,6 +107,7 @@ export interface Spec extends TurboModule {
   +getSupportedPerformanceEntryTypes?: () => $ReadOnlyArray<RawPerformanceEntryType>;
 
   +setCurrentTimeStampForTesting?: (timeStamp: number) => void;
+  +clearEventCountsForTesting?: () => void;
 }
 
 export default (TurboModuleRegistry.get<Spec>('NativePerformanceCxx'): ?Spec);