Assume NativePerformance will be available if the Performance module is loaded

packages/react-native/Libraries/Core/setUpPerformance.js

@@ -8,12 +8,13 @@
  * @format
  */
 
-import Performance from '../../src/private/webapis/performance/Performance';
 import NativePerformance from '../../src/private/webapis/performance/specs/NativePerformance';
 
 // In case if the native implementation of the Performance API is available, use it,
 // otherwise fall back to the legacy/default one, which only defines 'Performance.now()'
 if (NativePerformance) {
+  const Performance =
+    require('../../src/private/webapis/performance/Performance').default;
   // $FlowExpectedError[cannot-write]
   global.performance = new Performance();
 } else {

packages/react-native/src/private/webapis/performance/EventTiming.js

@@ -15,9 +15,11 @@ import type {
   PerformanceEntryJSON,
 } from './PerformanceEntry';
 
-import {warnNoNativePerformance} from './internals/Utilities';
 import {PerformanceEntry} from './PerformanceEntry';
-import NativePerformance from './specs/NativePerformance';
+import MaybeNativePerformance from './specs/NativePerformance';
+import nullthrows from 'nullthrows';
+
+const NativePerformance = nullthrows(MaybeNativePerformance);
 
 export type PerformanceEventTimingJSON = {
   ...PerformanceEntryJSON,
@@ -86,14 +88,8 @@ function getCachedEventCounts(): Map<string, number> {
     return cachedEventCounts;
   }
 
-  if (!NativePerformance || !NativePerformance?.getEventCounts) {
-    warnNoNativePerformance();
-    cachedEventCounts = new Map();
-    return cachedEventCounts;
-  }
-
   const eventCounts = new Map<string, number>(
-    NativePerformance.getEventCounts?.() ?? [],
+    NativePerformance.getEventCounts() ?? [],
   );
   cachedEventCounts = eventCounts;
 

packages/react-native/src/private/webapis/performance/Performance.js

@@ -35,8 +35,9 @@ import {
 } from './internals/Utilities';
 import MemoryInfo from './MemoryInfo';
 import ReactNativeStartupTiming from './ReactNativeStartupTiming';
-import NativePerformance from './specs/NativePerformance';
+import MaybeNativePerformance from './specs/NativePerformance';
 import {PerformanceMark, PerformanceMeasure} from './UserTiming';
+import nullthrows from 'nullthrows';
 
 export type PerformanceMeasureOptions =
   | $ReadOnly<{
@@ -58,11 +59,13 @@ export type PerformanceMeasureOptions =
 const ENTRY_TYPES_AVAILABLE_FROM_TIMELINE: $ReadOnlyArray<PerformanceEntryType> =
   ['mark', 'measure'];
 
-const cachedReportMark = NativePerformance?.reportMark;
-const cachedReportMeasure = NativePerformance?.reportMeasure;
-const cachedGetMarkTime = NativePerformance?.getMarkTime;
-const cachedNativeClearMarks = NativePerformance?.clearMarks;
-const cachedNativeClearMeasures = NativePerformance?.clearMeasures;
+const NativePerformance = nullthrows(MaybeNativePerformance);
+
+const cachedReportMark = NativePerformance.reportMark;
+const cachedReportMeasure = NativePerformance.reportMeasure;
+const cachedGetMarkTime = NativePerformance.getMarkTime;
+const cachedNativeClearMarks = NativePerformance.clearMarks;
+const cachedNativeClearMeasures = NativePerformance.clearMeasures;
 
 const MARK_OPTIONS_REUSABLE_OBJECT: {...PerformanceMarkOptions} = {
   startTime: 0,
@@ -98,53 +101,46 @@ export default class Performance {
 
   // Get the current JS memory information.
   get memory(): MemoryInfo {
-    if (NativePerformance?.getSimpleMemoryInfo) {
-      // JSI API implementations may have different variants of names for the JS
-      // heap information we need here. We will parse the result based on our
-      // guess of the implementation for now.
-      const memoryInfo = NativePerformance.getSimpleMemoryInfo();
-      if (memoryInfo.hasOwnProperty('hermes_heapSize')) {
-        // We got memory information from Hermes
-        const {
-          hermes_heapSize: totalJSHeapSize,
-          hermes_allocatedBytes: usedJSHeapSize,
-        } = memoryInfo;
-
-        return new MemoryInfo({
-          jsHeapSizeLimit: null, // We don't know the heap size limit from Hermes.
-          totalJSHeapSize,
-          usedJSHeapSize,
-        });
-      } else {
-        // JSC and V8 has no native implementations for memory information in JSI::Instrumentation
-        return new MemoryInfo();
-      }
+    // JSI API implementations may have different variants of names for the JS
+    // heap information we need here. We will parse the result based on our
+    // guess of the implementation for now.
+    const memoryInfo = NativePerformance.getSimpleMemoryInfo();
+    if (memoryInfo.hasOwnProperty('hermes_heapSize')) {
+      // We got memory information from Hermes
+      const {
+        hermes_heapSize: totalJSHeapSize,
+        hermes_allocatedBytes: usedJSHeapSize,
+      } = memoryInfo;
+
+      return new MemoryInfo({
+        jsHeapSizeLimit: null, // We don't know the heap size limit from Hermes.
+        totalJSHeapSize,
+        usedJSHeapSize,
+      });
+    } else {
+      // JSC and V8 has no native implementations for memory information in JSI::Instrumentation
+      return new MemoryInfo();
     }
-
-    return new MemoryInfo();
   }
 
   // Startup metrics is not used in web, but only in React Native.
   get rnStartupTiming(): ReactNativeStartupTiming {
-    if (NativePerformance?.getReactNativeStartupTiming) {
-      const {
-        startTime,
-        endTime,
-        initializeRuntimeStart,
-        initializeRuntimeEnd,
-        executeJavaScriptBundleEntryPointStart,
-        executeJavaScriptBundleEntryPointEnd,
-      } = NativePerformance.getReactNativeStartupTiming();
-      return new ReactNativeStartupTiming({
-        startTime,
-        endTime,
-        initializeRuntimeStart,
-        initializeRuntimeEnd,
-        executeJavaScriptBundleEntryPointStart,
-        executeJavaScriptBundleEntryPointEnd,
-      });
-    }
-    return new ReactNativeStartupTiming();
+    const {
+      startTime,
+      endTime,
+      initializeRuntimeStart,
+      initializeRuntimeEnd,
+      executeJavaScriptBundleEntryPointStart,
+      executeJavaScriptBundleEntryPointEnd,
+    } = NativePerformance.getReactNativeStartupTiming();
+    return new ReactNativeStartupTiming({
+      startTime,
+      endTime,
+      initializeRuntimeStart,
+      initializeRuntimeEnd,
+      executeJavaScriptBundleEntryPointStart,
+      executeJavaScriptBundleEntryPointEnd,
+    });
   }
 
   mark(
@@ -217,11 +213,6 @@ export default class Performance {
   }
 
   clearMarks(markName?: string): void {
-    if (!cachedNativeClearMarks) {
-      warnNoNativePerformance();
-      return;
-    }
-
     cachedNativeClearMarks(markName);
   }
 
@@ -414,11 +405,6 @@ export default class Performance {
   }
 
   clearMeasures(measureName?: string): void {
-    if (!cachedNativeClearMeasures) {
-      warnNoNativePerformance();
-      return;
-    }
-
     cachedNativeClearMeasures(measureName);
   }
 
@@ -434,10 +420,6 @@ export default class Performance {
    * https://www.w3.org/TR/performance-timeline/#extensions-to-the-performance-interface
    */
   getEntries(): PerformanceEntryList {
-    if (!NativePerformance?.getEntries) {
-      warnNoNativePerformance();
-      return [];
-    }
     return NativePerformance.getEntries().map(rawToPerformanceEntry);
   }
 
@@ -450,11 +432,6 @@ export default class Performance {
       return [];
     }
 
-    if (!NativePerformance?.getEntriesByType) {
-      warnNoNativePerformance();
-      return [];
-    }
-
     return NativePerformance.getEntriesByType(
       performanceEntryTypeToRaw(entryType),
     ).map(rawToPerformanceEntry);
@@ -472,11 +449,6 @@ export default class Performance {
       return [];
     }
 
-    if (!NativePerformance?.getEntriesByName) {
-      warnNoNativePerformance();
-      return [];
-    }
-
     return NativePerformance.getEntriesByName(
       entryName,
       entryType != null ? performanceEntryTypeToRaw(entryType) : undefined,

packages/react-native/src/private/webapis/performance/PerformanceObserver.js

@@ -21,12 +21,13 @@ import {
   rawToPerformanceEntry,
   rawToPerformanceEntryType,
 } from './internals/RawPerformanceEntry';
-import {warnNoNativePerformance} from './internals/Utilities';
-import NativePerformance from './specs/NativePerformance';
+import MaybeNativePerformance from './specs/NativePerformance';
 import nullthrows from 'nullthrows';
 
 export {PerformanceEntry} from './PerformanceEntry';
 
+const NativePerformance = nullthrows(MaybeNativePerformance);
+
 export class PerformanceObserverEntryList {
   #entries: PerformanceEntryList;
 
@@ -75,13 +76,6 @@ export interface PerformanceObserverInit {
 }
 
 function getSupportedPerformanceEntryTypes(): $ReadOnlyArray<PerformanceEntryType> {
-  if (!NativePerformance) {
-    return Object.freeze([]);
-  }
-  if (!NativePerformance.getSupportedPerformanceEntryTypes) {
-    // fallback if getSupportedPerformanceEntryTypes is not defined on native side
-    return Object.freeze(['mark', 'measure', 'event']);
-  }
   return Object.freeze(
     NativePerformance.getSupportedPerformanceEntryTypes().map(
       rawToPerformanceEntryType,
@@ -120,11 +114,6 @@ export class PerformanceObserver {
   }
 
   observe(options: PerformanceObserverInit): void {
-    if (!NativePerformance || NativePerformance.observe == null) {
-      warnNoNativePerformance();
-      return;
-    }
-
     this.#validateObserveOptions(options);
 
     if (this.#nativeObserverHandle == null) {
@@ -135,12 +124,12 @@ export class PerformanceObserver {
 
     if (options.entryTypes) {
       this.#type = 'multiple';
-      NativePerformance.observe?.(observerHandle, {
+      NativePerformance.observe(observerHandle, {
         entryTypes: options.entryTypes.map(performanceEntryTypeToRaw),
       });
     } else if (options.type) {
       this.#type = 'single';
-      NativePerformance.observe?.(observerHandle, {
+      NativePerformance.observe(observerHandle, {
         type: performanceEntryTypeToRaw(options.type),
         buffered: options.buffered,
         durationThreshold: options.durationThreshold,
@@ -149,29 +138,19 @@ export class PerformanceObserver {
   }
 
   disconnect(): void {
-    if (!NativePerformance) {
-      warnNoNativePerformance();
-      return;
-    }
-
-    if (this.#nativeObserverHandle == null || !NativePerformance.disconnect) {
+    if (this.#nativeObserverHandle == null) {
       return;
     }
 
     NativePerformance.disconnect(this.#nativeObserverHandle);
   }
 
   #createNativeObserver(): OpaqueNativeObserverHandle | null {
-    if (!NativePerformance || !NativePerformance.createObserver) {
-      warnNoNativePerformance();
-      return null;
-    }
-
     this.#calledAtLeastOnce = false;
 
     const observerHandle: OpaqueNativeObserverHandle =
       NativePerformance.createObserver(() => {
-        const rawEntries = NativePerformance.takeRecords?.(
+        const rawEntries = NativePerformance.takeRecords(
           observerHandle,
           true, // sort records
         );
@@ -185,7 +164,7 @@ export class PerformanceObserver {
         let droppedEntriesCount = 0;
         if (!this.#calledAtLeastOnce) {
           droppedEntriesCount =
-            NativePerformance.getDroppedEntriesCount?.(observerHandle) ?? 0;
+            NativePerformance.getDroppedEntriesCount(observerHandle);
           this.#calledAtLeastOnce = true;
         }
 

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

@@ -13,7 +13,7 @@ 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 MaybeNativePerformance from '../specs/NativePerformance';
 import * as Fantom from '@react-native/fantom';
 import nullthrows from 'nullthrows';
 import {useState} from 'react';
@@ -22,6 +22,8 @@ import setUpPerformanceObserver from 'react-native/src/private/setup/setUpPerfor
 import {PerformanceEventTiming} from 'react-native/src/private/webapis/performance/EventTiming';
 import {PerformanceObserver} from 'react-native/src/private/webapis/performance/PerformanceObserver';
 
+const NativePerformance = nullthrows(MaybeNativePerformance);
+
 setUpPerformanceObserver();
 
 declare var performance: Performance;
@@ -193,7 +195,7 @@ describe('Event Timing API', () => {
   });
 
   it('reports number of dispatched events via performance.eventCounts', () => {
-    NativePerformance?.clearEventCountsForTesting?.();
+    NativePerformance.clearEventCountsForTesting?.();
 
     const root = Fantom.createRoot();
     Fantom.runTask(() => {