Remove enableUserBlockingEvents flag (#16882)

Seems like this worked out. We can clean up the flag now.

Author: sebmarkbage

packages/react-dom/src/events/DOMEventResponderSystem.js

@@ -39,7 +39,6 @@ import {
   UserBlockingEvent,
   DiscreteEvent,
 } from 'shared/ReactTypes';
-import {enableUserBlockingEvents} from 'shared/ReactFeatureFlags';
 
 // Intentionally not named imports because Rollup would use dynamic dispatch for
 // CommonJS interop named imports.
@@ -104,13 +103,9 @@ const eventResponderContext: ReactDOMResponderContext = {
         break;
       }
       case UserBlockingEvent: {
-        if (enableUserBlockingEvents) {
-          runWithPriority(UserBlockingPriority, () =>
-            executeUserEventHandler(eventListener, eventValue),
-          );
-        } else {
-          executeUserEventHandler(eventListener, eventValue);
-        }
+        runWithPriority(UserBlockingPriority, () =>
+          executeUserEventHandler(eventListener, eventValue),
+        );
         break;
       }
       case ContinuousEvent: {

packages/react-dom/src/events/ReactDOMEventListener.js

@@ -62,10 +62,7 @@ import SimpleEventPlugin from './SimpleEventPlugin';
 import {getRawEventName} from './DOMTopLevelEventTypes';
 import {passiveBrowserEventsSupported} from './checkPassiveEvents';
 
-import {
-  enableFlareAPI,
-  enableUserBlockingEvents,
-} from 'shared/ReactFeatureFlags';
+import {enableFlareAPI} from 'shared/ReactFeatureFlags';
 import {
   UserBlockingEvent,
   ContinuousEvent,
@@ -298,14 +295,10 @@ function dispatchUserBlockingUpdate(
   eventSystemFlags,
   nativeEvent,
 ) {
-  if (enableUserBlockingEvents) {
-    runWithPriority(
-      UserBlockingPriority,
-      dispatchEvent.bind(null, topLevelType, eventSystemFlags, nativeEvent),
-    );
-  } else {
-    dispatchEvent(topLevelType, eventSystemFlags, nativeEvent);
-  }
+  runWithPriority(
+    UserBlockingPriority,
+    dispatchEvent.bind(null, topLevelType, eventSystemFlags, nativeEvent),
+  );
 }
 
 function dispatchEventForPluginEventSystem(

packages/react-dom/src/events/__tests__/ChangeEventPlugin-test.internal.js

@@ -750,8 +750,6 @@ describe('ChangeEventPlugin', () => {
     it('mouse enter/leave should be user-blocking but not discrete', async () => {
       // This is currently behind a feature flag
       jest.resetModules();
-      ReactFeatureFlags = require('shared/ReactFeatureFlags');
-      ReactFeatureFlags.enableUserBlockingEvents = true;
       React = require('react');
       ReactDOM = require('react-dom');
       TestUtils = require('react-dom/test-utils');

packages/react-interactions/events/src/dom/__tests__/Hover-test.internal.js

@@ -22,7 +22,6 @@ function initializeModules(hasPointerEvents) {
   setPointerEvent(hasPointerEvents);
   ReactFeatureFlags = require('shared/ReactFeatureFlags');
   ReactFeatureFlags.enableFlareAPI = true;
-  ReactFeatureFlags.enableUserBlockingEvents = true;
   React = require('react');
   ReactDOM = require('react-dom');
   HoverResponder = require('react-interactions/events/hover').HoverResponder;

packages/react-interactions/events/src/dom/__tests__/Input-test.internal.js

@@ -35,7 +35,6 @@ const modulesInit = () => {
   ReactFeatureFlags = require('shared/ReactFeatureFlags');
   ReactFeatureFlags.enableFlareAPI = true;
   ReactFeatureFlags.debugRenderPhaseSideEffectsForStrictMode = false;
-  ReactFeatureFlags.enableUserBlockingEvents = true;
   React = require('react');
   ReactDOM = require('react-dom');
   Scheduler = require('scheduler');

packages/react-interactions/events/src/dom/__tests__/MixedResponders-test-internal.js

@@ -236,7 +236,6 @@ describe('mixing responders with the heritage event system', () => {
   describe('mixing the Input and Press repsonders', () => {
     it('is async for non-input events', () => {
       ReactFeatureFlags.debugRenderPhaseSideEffectsForStrictMode = false;
-      ReactFeatureFlags.enableUserBlockingEvents = true;
       const useTap = require('react-interactions/events/tap').useTap;
       const useInput = require('react-interactions/events/input').useInput;
       const root = ReactDOM.unstable_createRoot(container);

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

@@ -31,7 +31,6 @@ import {
   UserBlockingEvent,
   DiscreteEvent,
 } from './ReactNativeTypes';
-import {enableUserBlockingEvents} from 'shared/ReactFeatureFlags';
 import warning from 'shared/warning';
 import invariant from 'shared/invariant';
 
@@ -95,13 +94,9 @@ const eventResponderContext: ReactNativeResponderContext = {
         break;
       }
       case UserBlockingEvent: {
-        if (enableUserBlockingEvents) {
-          runWithPriority(UserBlockingPriority, () =>
-            executeUserEventHandler(eventListener, eventValue),
-          );
-        } else {
-          executeUserEventHandler(eventListener, eventValue);
-        }
+        runWithPriority(UserBlockingPriority, () =>
+          executeUserEventHandler(eventListener, eventValue),
+        );
         break;
       }
       case ContinuousEvent: {

packages/shared/ReactFeatureFlags.js

@@ -80,11 +80,6 @@ export const warnAboutUnmockedScheduler = false;
 // *except* in some of our own tests, where we test incremental loading states.
 export const flushSuspenseFallbacksInTests = true;
 
-// Changes priority of some events like mousemove to user-blocking priority,
-// but without making them discrete. The flag exists in case it causes
-// starvation problems.
-export const enableUserBlockingEvents = false;
-
 // Add a callback property to suspense to notify which promises are currently
 // in the update queue. This allows reporting and tracing of what is causing
 // the user to see a loading state.

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

@@ -38,7 +38,6 @@ export const enableScopeAPI = false;
 export const enableJSXTransformAPI = false;
 export const warnAboutUnmockedScheduler = true;
 export const flushSuspenseFallbacksInTests = true;
-export const enableUserBlockingEvents = false;
 export const enableSuspenseCallback = false;
 export const warnAboutDefaultPropsOnFunctionComponents = false;
 export const warnAboutStringRefs = false;

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

@@ -33,7 +33,6 @@ export const enableScopeAPI = false;
 export const enableJSXTransformAPI = false;
 export const warnAboutUnmockedScheduler = false;
 export const flushSuspenseFallbacksInTests = true;
-export const enableUserBlockingEvents = false;
 export const enableSuspenseCallback = false;
 export const warnAboutDefaultPropsOnFunctionComponents = false;
 export const warnAboutStringRefs = false;