Land warnOnSubscriptionInsideStartTransition flag (#23353)

We're including this in 18. The feature was already enabled — this just
removes the flag.

Author: acdlite

packages/react-reconciler/src/ReactFiberHooks.new.js

@@ -109,7 +109,6 @@ import {
   entangleTransitions as entangleLegacyQueueTransitions,
 } from './ReactUpdateQueue.new';
 import {pushInterleavedQueue} from './ReactFiberInterleavedUpdates.new';
-import {warnOnSubscriptionInsideStartTransition} from 'shared/ReactFeatureFlags';
 import {getTreeId} from './ReactFiberTreeContext.new';
 
 const {ReactCurrentDispatcher, ReactCurrentBatchConfig} = ReactSharedInternals;
@@ -1992,11 +1991,7 @@ function startTransition(setPending, callback) {
 
     ReactCurrentBatchConfig.transition = prevTransition;
     if (__DEV__) {
-      if (
-        prevTransition === null &&
-        warnOnSubscriptionInsideStartTransition &&
-        currentTransition._updatedFibers
-      ) {
+      if (prevTransition === null && currentTransition._updatedFibers) {
         const updatedFibersCount = currentTransition._updatedFibers.size;
         if (updatedFibersCount > 10) {
           console.warn(

packages/react-reconciler/src/ReactFiberHooks.old.js

@@ -109,7 +109,6 @@ import {
   entangleTransitions as entangleLegacyQueueTransitions,
 } from './ReactUpdateQueue.old';
 import {pushInterleavedQueue} from './ReactFiberInterleavedUpdates.old';
-import {warnOnSubscriptionInsideStartTransition} from 'shared/ReactFeatureFlags';
 import {getTreeId} from './ReactFiberTreeContext.old';
 
 const {ReactCurrentDispatcher, ReactCurrentBatchConfig} = ReactSharedInternals;
@@ -1992,11 +1991,7 @@ function startTransition(setPending, callback) {
 
     ReactCurrentBatchConfig.transition = prevTransition;
     if (__DEV__) {
-      if (
-        prevTransition === null &&
-        warnOnSubscriptionInsideStartTransition &&
-        currentTransition._updatedFibers
-      ) {
+      if (prevTransition === null && currentTransition._updatedFibers) {
         const updatedFibersCount = currentTransition._updatedFibers.size;
         if (updatedFibersCount > 10) {
           console.warn(

packages/react-reconciler/src/ReactFiberWorkLoop.new.js

@@ -31,7 +31,6 @@ import {
   disableSchedulerTimeoutInWorkLoop,
   enableStrictEffects,
   enableUpdaterTracking,
-  warnOnSubscriptionInsideStartTransition,
   enableCache,
 } from 'shared/ReactFeatureFlags';
 import ReactSharedInternals from 'shared/ReactSharedInternals';
@@ -397,11 +396,7 @@ export function requestUpdateLane(fiber: Fiber): Lane {
 
   const isTransition = requestCurrentTransition() !== NoTransition;
   if (isTransition) {
-    if (
-      __DEV__ &&
-      warnOnSubscriptionInsideStartTransition &&
-      ReactCurrentBatchConfig.transition !== null
-    ) {
+    if (__DEV__ && ReactCurrentBatchConfig.transition !== null) {
       const transition = ReactCurrentBatchConfig.transition;
       if (!transition._updatedFibers) {
         transition._updatedFibers = new Set();

packages/react-reconciler/src/ReactFiberWorkLoop.old.js

@@ -31,7 +31,6 @@ import {
   disableSchedulerTimeoutInWorkLoop,
   enableStrictEffects,
   enableUpdaterTracking,
-  warnOnSubscriptionInsideStartTransition,
   enableCache,
 } from 'shared/ReactFeatureFlags';
 import ReactSharedInternals from 'shared/ReactSharedInternals';
@@ -397,11 +396,7 @@ export function requestUpdateLane(fiber: Fiber): Lane {
 
   const isTransition = requestCurrentTransition() !== NoTransition;
   if (isTransition) {
-    if (
-      __DEV__ &&
-      warnOnSubscriptionInsideStartTransition &&
-      ReactCurrentBatchConfig.transition !== null
-    ) {
+    if (__DEV__ && ReactCurrentBatchConfig.transition !== null) {
       const transition = ReactCurrentBatchConfig.transition;
       if (!transition._updatedFibers) {
         transition._updatedFibers = new Set();

packages/react/src/ReactStartTransition.js

@@ -8,7 +8,6 @@
  */
 
 import ReactCurrentBatchConfig from './ReactCurrentBatchConfig';
-import {warnOnSubscriptionInsideStartTransition} from 'shared/ReactFeatureFlags';
 
 export function startTransition(scope: () => void) {
   const prevTransition = ReactCurrentBatchConfig.transition;
@@ -24,11 +23,7 @@ export function startTransition(scope: () => void) {
     ReactCurrentBatchConfig.transition = prevTransition;
 
     if (__DEV__) {
-      if (
-        prevTransition === null &&
-        warnOnSubscriptionInsideStartTransition &&
-        currentTransition._updatedFibers
-      ) {
+      if (prevTransition === null && currentTransition._updatedFibers) {
         const updatedFibersCount = currentTransition._updatedFibers.size;
         if (updatedFibersCount > 10) {
           console.warn(

packages/react/src/__tests__/ReactStartTransition-test.js

@@ -27,7 +27,6 @@ describe('ReactStartTransition', () => {
     useTransition = React.useTransition;
   });
 
-  // @gate warnOnSubscriptionInsideStartTransition || !__DEV__
   it('Warns if a suspicious number of fibers are updated inside startTransition', () => {
     const subs = new Set();
     const useUserSpaceSubscription = () => {

packages/shared/ReactFeatureFlags.js

@@ -13,7 +13,6 @@
 // Flags that can likely be deleted or landed without consequences
 // -----------------------------------------------------------------------------
 
-export const warnOnSubscriptionInsideStartTransition = false;
 export const enableSuspenseServerRenderer = true;
 export const enableSelectiveHydration = true;
 export const warnAboutDeprecatedLifecycles = true;

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

@@ -49,7 +49,6 @@ export const disableTextareaChildren = false;
 export const disableModulePatternComponents = false;
 export const warnUnstableRenderSubtreeIntoContainer = false;
 export const warnAboutSpreadingKeyToJSX = false;
-export const warnOnSubscriptionInsideStartTransition = false;
 export const enableSuspenseAvoidThisFallback = false;
 export const enableSuspenseAvoidThisFallbackFizz = false;
 export const enableCapturePhaseSelectiveHydrationWithoutDiscreteEventReplay = true;

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

@@ -40,7 +40,6 @@ export const disableTextareaChildren = false;
 export const disableModulePatternComponents = false;
 export const warnUnstableRenderSubtreeIntoContainer = false;
 export const warnAboutSpreadingKeyToJSX = false;
-export const warnOnSubscriptionInsideStartTransition = false;
 export const enableSuspenseAvoidThisFallback = false;
 export const enableSuspenseAvoidThisFallbackFizz = false;
 export const enableCapturePhaseSelectiveHydrationWithoutDiscreteEventReplay = true;

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

@@ -40,7 +40,6 @@ export const disableTextareaChildren = false;
 export const disableModulePatternComponents = false;
 export const warnUnstableRenderSubtreeIntoContainer = false;
 export const warnAboutSpreadingKeyToJSX = false;
-export const warnOnSubscriptionInsideStartTransition = false;
 export const enableSuspenseAvoidThisFallback = false;
 export const enableSuspenseAvoidThisFallbackFizz = false;
 export const enableCapturePhaseSelectiveHydrationWithoutDiscreteEventReplay = true;