Added new feature flag, enableSuspenseLayoutEffectSemantics

Author: Brian Vaughn

packages/shared/ReactFeatureFlags.js

@@ -125,6 +125,11 @@ export const skipUnmountedBoundaries = false;
 // aggressiveness.
 export const deletedTreeCleanUpLevel = 1;
 
+// Destroy layout effects for components that are hidden because something suspended in an update
+// and recreate them when they are shown again (after the suspended boundary has resolved).
+// Note that this should be an uncommon use case and can be avoided by using the transition API.
+export const enableSuspenseLayoutEffectSemantics = false;
+
 // --------------------------
 // Future APIs to be deprecated
 // --------------------------

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

@@ -47,6 +47,7 @@ export const enableFilterEmptyStringAttributesDOM = false;
 export const disableNativeComponentFrames = false;
 export const skipUnmountedBoundaries = false;
 export const deletedTreeCleanUpLevel = 1;
+export const enableSuspenseLayoutEffectSemantics = false;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;

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

@@ -46,6 +46,7 @@ export const enableFilterEmptyStringAttributesDOM = false;
 export const disableNativeComponentFrames = false;
 export const skipUnmountedBoundaries = false;
 export const deletedTreeCleanUpLevel = 1;
+export const enableSuspenseLayoutEffectSemantics = false;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;

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

@@ -46,6 +46,7 @@ export const enableFilterEmptyStringAttributesDOM = false;
 export const disableNativeComponentFrames = false;
 export const skipUnmountedBoundaries = false;
 export const deletedTreeCleanUpLevel = 1;
+export const enableSuspenseLayoutEffectSemantics = false;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;

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

@@ -46,6 +46,7 @@ export const enableFilterEmptyStringAttributesDOM = false;
 export const disableNativeComponentFrames = false;
 export const skipUnmountedBoundaries = false;
 export const deletedTreeCleanUpLevel = 1;
+export const enableSuspenseLayoutEffectSemantics = false;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;

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

@@ -46,6 +46,7 @@ export const enableFilterEmptyStringAttributesDOM = false;
 export const disableNativeComponentFrames = false;
 export const skipUnmountedBoundaries = false;
 export const deletedTreeCleanUpLevel = 1;
+export const enableSuspenseLayoutEffectSemantics = false;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;

packages/shared/forks/ReactFeatureFlags.testing.js

@@ -46,6 +46,7 @@ export const enableFilterEmptyStringAttributesDOM = false;
 export const disableNativeComponentFrames = false;
 export const skipUnmountedBoundaries = false;
 export const deletedTreeCleanUpLevel = 1;
+export const enableSuspenseLayoutEffectSemantics = false;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;

packages/shared/forks/ReactFeatureFlags.testing.www.js

@@ -46,6 +46,7 @@ export const enableFilterEmptyStringAttributesDOM = false;
 export const disableNativeComponentFrames = false;
 export const skipUnmountedBoundaries = true;
 export const deletedTreeCleanUpLevel = 1;
+export const enableSuspenseLayoutEffectSemantics = false;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;

packages/shared/forks/ReactFeatureFlags.www-dynamic.js

@@ -18,6 +18,7 @@ export const disableInputAttributeSyncing = __VARIANT__;
 export const enableFilterEmptyStringAttributesDOM = __VARIANT__;
 export const enableLegacyFBSupport = __VARIANT__;
 export const skipUnmountedBoundaries = __VARIANT__;
+export const enableSuspenseLayoutEffectSemantics = __VARIANT__;
 
 // Enable this flag to help with concurrent mode debugging.
 // It logs information to the console about React scheduling, rendering, and commit phases.

packages/shared/forks/ReactFeatureFlags.www.js

@@ -28,6 +28,7 @@ export const {
   skipUnmountedBoundaries,
   enableStrictEffects,
   createRootStrictEffectsByDefault,
+  enableSuspenseLayoutEffectSemantics,
   enableUseRefAccessWarning,
   disableNativeComponentFrames,
   disableSchedulerTimeoutInWorkLoop,