Add enableAddPropertiesFastPath feature flag

packages/react-native-renderer/src/ReactNativeAttributePayload.js

@@ -15,6 +15,7 @@ import {
 import isArray from 'shared/isArray';
 
 import {enableEarlyReturnForPropDiffing} from 'shared/ReactFeatureFlags';
+import {enableAddPropertiesFastPath} from 'shared/ReactFeatureFlags';
 
 import type {AttributeConfiguration} from './ReactNativeTypes';
 
@@ -514,7 +515,11 @@ function addProperties(
   props: Object,
   validAttributes: AttributeConfiguration,
 ): null | Object {
-  return fastAddProperties(updatePayload, props, validAttributes);
+  if (enableAddPropertiesFastPath) {
+    return fastAddProperties(updatePayload, props, validAttributes);
+  } else {
+    return diffProperties(updatePayload, emptyObject, props, validAttributes);
+  }
 }
 
 /**

packages/shared/ReactFeatureFlags.js

@@ -123,6 +123,8 @@ export const enableServerComponentLogs = __EXPERIMENTAL__;
 
 export const enableEarlyReturnForPropDiffing = false;
 
+export const enableAddPropertiesFastPath = false;
+
 /**
  * Enables an expiration time for retry lanes to avoid starvation.
  */

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

@@ -29,3 +29,4 @@ export const enableUnifiedSyncLane = __VARIANT__;
 export const passChildrenWhenCloningPersistedNodes = __VARIANT__;
 export const useModernStrictMode = __VARIANT__;
 export const disableDefaultPropsExceptForClasses = __VARIANT__;
+export const enableAddPropertiesFastPath = __VARIANT__;

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

@@ -31,6 +31,7 @@ export const {
   passChildrenWhenCloningPersistedNodes,
   useModernStrictMode,
   disableDefaultPropsExceptForClasses,
+  enableAddPropertiesFastPath,
 } = dynamicFlags;
 
 // The rest of the flags are static for better dead code elimination.

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

@@ -103,6 +103,7 @@ export const enableDO_NOT_USE_disableStrictPassiveEffect = false;
 export const passChildrenWhenCloningPersistedNodes = false;
 export const enableEarlyReturnForPropDiffing = false;
 export const enableAsyncIterableChildren = false;
+export const enableAddPropertiesFastPath = false;
 
 export const renameElementSymbol = true;
 

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

@@ -78,6 +78,7 @@ export const enableServerComponentKeys = true;
 export const enableServerComponentLogs = true;
 export const enableInfiniteRenderLoopDetection = false;
 export const enableEarlyReturnForPropDiffing = false;
+export const enableAddPropertiesFastPath = false;
 
 export const renameElementSymbol = true;
 

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

@@ -89,6 +89,7 @@ export const disableDOMTestUtils = false;
 
 export const disableDefaultPropsExceptForClasses = false;
 export const enableEarlyReturnForPropDiffing = false;
+export const enableAddPropertiesFastPath = false;
 
 export const renameElementSymbol = false;
 

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

@@ -89,6 +89,7 @@ export const disableDOMTestUtils = false;
 
 export const disableDefaultPropsExceptForClasses = false;
 export const enableEarlyReturnForPropDiffing = false;
+export const enableAddPropertiesFastPath = false;
 
 export const renameElementSymbol = false;
 

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

@@ -31,6 +31,7 @@ export const enableNoCloningMemoCache = __VARIANT__;
 export const retryLaneExpirationMs = 5000;
 export const syncLaneExpirationMs = 250;
 export const transitionLaneExpirationMs = 5000;
+export const enableAddPropertiesFastPath = __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

@@ -35,6 +35,7 @@ export const {
   favorSafetyOverHydrationPerf,
   disableDefaultPropsExceptForClasses,
   enableNoCloningMemoCache,
+  enableAddPropertiesFastPath,
 } = dynamicFeatureFlags;
 
 // On WWW, __EXPERIMENTAL__ is used for a new modern build.