Add Feature Flag

packages/shared/ReactFeatureFlags.js

@@ -77,6 +77,9 @@ export const enableLegacyFBSupport = false;
 // likely to include in an upcoming release.
 // -----------------------------------------------------------------------------
 
+// Yield to the browser event loop and not just the scheduler event loop before passive effects.
+export const enableYieldingBeforePassive = __EXPERIMENTAL__;
+
 export const enableLegacyCache = __EXPERIMENTAL__;
 
 export const enableAsyncIterableChildren = __EXPERIMENTAL__;

packages/shared/forks/ReactFeatureFlags.native-fb.js

@@ -82,6 +82,7 @@ export const syncLaneExpirationMs = 250;
 export const transitionLaneExpirationMs = 5000;
 export const useModernStrictMode = true;
 export const enableHydrationLaneScheduling = true;
+export const enableYieldingBeforePassive = true;
 
 // Flow magic to verify the exports of this file match the original version.
 ((((null: any): ExportsType): FeatureFlagsType): ExportsType);

packages/shared/forks/ReactFeatureFlags.native-oss.js

@@ -76,6 +76,8 @@ export const enableUseResourceEffectHook = false;
 
 export const enableHydrationLaneScheduling = true;
 
+export const enableYieldingBeforePassive = true;
+
 // Profiling Only
 export const enableProfilerTimer = __PROFILE__;
 export const enableProfilerCommitHooks = __PROFILE__;

packages/shared/forks/ReactFeatureFlags.test-renderer.js

@@ -72,6 +72,8 @@ export const enableSiblingPrerendering = true;
 
 export const enableUseResourceEffectHook = false;
 
+export const enableYieldingBeforePassive = true;
+
 // TODO: This must be in sync with the main ReactFeatureFlags file because
 // the Test Renderer's value must be the same as the one used by the
 // react package.

packages/shared/forks/ReactFeatureFlags.test-renderer.native-fb.js

@@ -70,6 +70,7 @@ export const enableFabricCompleteRootInCommitPhase = false;
 export const enableSiblingPrerendering = true;
 export const enableUseResourceEffectHook = true;
 export const enableHydrationLaneScheduling = true;
+export const enableYieldingBeforePassive = true;
 
 // Flow magic to verify the exports of this file match the original version.
 ((((null: any): ExportsType): FeatureFlagsType): ExportsType);

packages/shared/forks/ReactFeatureFlags.test-renderer.www.js

@@ -84,5 +84,7 @@ export const enableUseResourceEffectHook = false;
 
 export const enableHydrationLaneScheduling = true;
 
+export const enableYieldingBeforePassive = true;
+
 // Flow magic to verify the exports of this file match the original version.
 ((((null: any): ExportsType): FeatureFlagsType): ExportsType);

packages/shared/forks/ReactFeatureFlags.www.js

@@ -57,6 +57,8 @@ export const enableMoveBefore = false;
 export const disableInputAttributeSyncing = false;
 export const enableLegacyFBSupport = true;
 
+export const enableYieldingBeforePassive = false;
+
 export const enableHydrationLaneScheduling = true;
 
 export const enableComponentPerformanceTrack = false;