Revert "Synchronously flush the transition lane scheduled in a popstate event (facebook#26025)"

This reverts commit d121c67.

Author: kassens

packages/react-art/src/ReactFiberConfigART.js

@@ -346,10 +346,6 @@ export function getCurrentEventPriority() {
   return DefaultEventPriority;
 }
 
-export function shouldAttemptEagerTransition() {
-  return false;
-}
-
 // The ART renderer is secondary to the React DOM renderer.
 export const isPrimaryRenderer = false;
 

packages/react-dom-bindings/src/client/ReactFiberConfigDOM.js

@@ -527,10 +527,6 @@ export function getCurrentEventPriority(): EventPriority {
   return getEventPriority(currentEvent.type);
 }
 
-export function shouldAttemptEagerTransition(): boolean {
-  return window.event && window.event.type === 'popstate';
-}
-
 export const isPrimaryRenderer = true;
 export const warnsIfNotActing = true;
 // This initialization code may run even on server environments

packages/react-dom/src/__tests__/ReactDOMFiberAsync-test.js

@@ -27,6 +27,7 @@ describe('ReactDOMFiberAsync', () => {
   let container;
 
   beforeEach(() => {
+    jest.resetModules();
     container = document.createElement('div');
     React = require('react');
     ReactDOM = require('react-dom');
@@ -39,7 +40,6 @@ describe('ReactDOMFiberAsync', () => {
     assertLog = InternalTestUtils.assertLog;
 
     document.body.appendChild(container);
-    window.event = undefined;
   });
 
   afterEach(() => {
@@ -566,139 +566,4 @@ describe('ReactDOMFiberAsync', () => {
 
     expect(container.textContent).toBe('new');
   });
-
-  it('should synchronously render the transition lane scheduled in a popState', async () => {
-    function App() {
-      const [syncState, setSyncState] = React.useState(false);
-      const [hasNavigated, setHasNavigated] = React.useState(false);
-      function onPopstate() {
-        Scheduler.log(`popState`);
-        React.startTransition(() => {
-          setHasNavigated(true);
-        });
-        setSyncState(true);
-      }
-      React.useEffect(() => {
-        window.addEventListener('popstate', onPopstate);
-        return () => {
-          window.removeEventListener('popstate', onPopstate);
-        };
-      }, []);
-      Scheduler.log(`render:${hasNavigated}/${syncState}`);
-      return null;
-    }
-    const root = ReactDOMClient.createRoot(container);
-    await act(async () => {
-      root.render(<App />);
-    });
-    assertLog(['render:false/false']);
-
-    await act(async () => {
-      const popStateEvent = new Event('popstate');
-      // Jest is not emulating window.event correctly in the microtask
-      window.event = popStateEvent;
-      window.dispatchEvent(popStateEvent);
-      queueMicrotask(() => {
-        window.event = undefined;
-      });
-    });
-
-    assertLog(['popState', 'render:true/true']);
-    await act(() => {
-      root.unmount();
-    });
-  });
-
-  it('Should not flush transition lanes if there is no transition scheduled in popState', async () => {
-    let setHasNavigated;
-    function App() {
-      const [syncState, setSyncState] = React.useState(false);
-      const [hasNavigated, _setHasNavigated] = React.useState(false);
-      setHasNavigated = _setHasNavigated;
-      function onPopstate() {
-        setSyncState(true);
-      }
-
-      React.useEffect(() => {
-        window.addEventListener('popstate', onPopstate);
-        return () => {
-          window.removeEventListener('popstate', onPopstate);
-        };
-      }, []);
-
-      Scheduler.log(`render:${hasNavigated}/${syncState}`);
-      return null;
-    }
-    const root = ReactDOMClient.createRoot(container);
-    await act(async () => {
-      root.render(<App />);
-    });
-    assertLog(['render:false/false']);
-
-    React.startTransition(() => {
-      setHasNavigated(true);
-    });
-    await act(async () => {
-      const popStateEvent = new Event('popstate');
-      // Jest is not emulating window.event correctly in the microtask
-      window.event = popStateEvent;
-      window.dispatchEvent(popStateEvent);
-      queueMicrotask(() => {
-        window.event = undefined;
-      });
-    });
-    assertLog(['render:false/true', 'render:true/true']);
-    await act(() => {
-      root.unmount();
-    });
-  });
-
-  it('transition lane in popState should yield if it suspends', async () => {
-    const never = {then() {}};
-    let _setText;
-
-    function App() {
-      const [shouldSuspend, setShouldSuspend] = React.useState(false);
-      const [text, setText] = React.useState('0');
-      _setText = setText;
-      if (shouldSuspend) {
-        Scheduler.log('Suspend!');
-        throw never;
-      }
-      function onPopstate() {
-        React.startTransition(() => {
-          setShouldSuspend(val => !val);
-        });
-      }
-      React.useEffect(() => {
-        window.addEventListener('popstate', onPopstate);
-        return () => window.removeEventListener('popstate', onPopstate);
-      }, []);
-      Scheduler.log(`Child:${shouldSuspend}/${text}`);
-      return text;
-    }
-
-    const root = ReactDOMClient.createRoot(container);
-    await act(async () => {
-      root.render(<App />);
-    });
-    assertLog(['Child:false/0']);
-
-    await act(() => {
-      const popStateEvent = new Event('popstate');
-      window.event = popStateEvent;
-      window.dispatchEvent(popStateEvent);
-      queueMicrotask(() => {
-        window.event = undefined;
-      });
-    });
-    assertLog(['Suspend!']);
-
-    await act(async () => {
-      _setText('1');
-    });
-    assertLog(['Child:false/1', 'Suspend!']);
-
-    root.unmount();
-  });
 });

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

@@ -334,10 +334,6 @@ export function getCurrentEventPriority(): * {
   return DefaultEventPriority;
 }
 
-export function shouldAttemptEagerTransition(): boolean {
-  return false;
-}
-
 // The Fabric renderer is secondary to the existing React Native renderer.
 export const isPrimaryRenderer = false;
 

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

@@ -265,10 +265,6 @@ export function getCurrentEventPriority(): * {
   return DefaultEventPriority;
 }
 
-export function shouldAttemptEagerTransition(): boolean {
-  return false;
-}
-
 // -------------------
 //     Mutation
 // -------------------

packages/react-noop-renderer/src/createReactNoop.js

@@ -526,10 +526,6 @@ function createReactNoop(reconciler: Function, useMutation: boolean) {
       return currentEventPriority;
     },
 
-    shouldAttemptEagerTransition(): boolean {
-      return false;
-    },
-
     now: Scheduler.unstable_now,
 
     isPrimaryRenderer: true,

packages/react-reconciler/src/ReactFiberRootScheduler.js

@@ -20,8 +20,6 @@ import {
   getNextLanes,
   includesSyncLane,
   markStarvedLanesAsExpired,
-  markRootEntangled,
-  mergeLanes,
 } from './ReactFiberLane';
 import {
   CommitContext,
@@ -51,11 +49,7 @@ import {
   IdleEventPriority,
   lanesToEventPriority,
 } from './ReactEventPriorities';
-import {
-  supportsMicrotasks,
-  scheduleMicrotask,
-  shouldAttemptEagerTransition,
-} from './ReactFiberConfig';
+import {supportsMicrotasks, scheduleMicrotask} from './ReactFiberConfig';
 
 import ReactSharedInternals from 'shared/ReactSharedInternals';
 const {ReactCurrentActQueue} = ReactSharedInternals;
@@ -78,8 +72,6 @@ let mightHavePendingSyncWork: boolean = false;
 
 let isFlushingWork: boolean = false;
 
-let currentEventTransitionLane: Lane = NoLanes;
-
 export function ensureRootIsScheduled(root: FiberRoot): void {
   // This function is called whenever a root receives an update. It does two
   // things 1) it ensures the root is in the root schedule, and 2) it ensures
@@ -246,14 +238,6 @@ function processRootScheduleInMicrotask() {
   let root = firstScheduledRoot;
   while (root !== null) {
     const next = root.next;
-
-    if (
-      currentEventTransitionLane !== NoLane &&
-      shouldAttemptEagerTransition()
-    ) {
-      markRootEntangled(root, mergeLanes(currentEventTransitionLane, SyncLane));
-    }
-
     const nextLanes = scheduleTaskForRootDuringMicrotask(root, currentTime);
     if (nextLanes === NoLane) {
       // This root has no more pending work. Remove it from the schedule. To
@@ -283,8 +267,6 @@ function processRootScheduleInMicrotask() {
     root = next;
   }
 
-  currentEventTransitionLane = NoLane;
-
   // At the end of the microtask, flush any pending synchronous work. This has
   // to come at the end, because it does actual rendering work that might throw.
   flushSyncWorkOnAllRoots();
@@ -490,11 +472,3 @@ function scheduleImmediateTask(cb: () => mixed) {
     Scheduler_scheduleCallback(ImmediateSchedulerPriority, cb);
   }
 }
-
-export function getCurrentEventTransitionLane(): Lane {
-  return currentEventTransitionLane;
-}
-
-export function setCurrentEventTransitionLane(lane: Lane): void {
-  currentEventTransitionLane = lane;
-}

packages/react-reconciler/src/ReactFiberWorkLoop.js

@@ -278,8 +278,6 @@ import {
   flushSyncWorkOnAllRoots,
   flushSyncWorkOnLegacyRootsOnly,
   getContinuationForRoot,
-  getCurrentEventTransitionLane,
-  setCurrentEventTransitionLane,
 } from './ReactFiberRootScheduler';
 import {getMaskedContext, getUnmaskedContext} from './ReactFiberContext';
 
@@ -584,6 +582,8 @@ const NESTED_PASSIVE_UPDATE_LIMIT = 50;
 let nestedPassiveUpdateCount: number = 0;
 let rootWithPassiveNestedUpdates: FiberRoot | null = null;
 
+let currentEventTransitionLane: Lanes = NoLanes;
+
 let isRunningInsertionEffect = false;
 
 export function getWorkInProgressRoot(): FiberRoot | null {
@@ -640,11 +640,11 @@ export function requestUpdateLane(fiber: Fiber): Lane {
     // The trick we use is to cache the first of each of these inputs within an
     // event. Then reset the cached values once we can be sure the event is
     // over. Our heuristic for that is whenever we enter a concurrent work loop.
-    if (getCurrentEventTransitionLane() === NoLane) {
+    if (currentEventTransitionLane === NoLane) {
       // All transitions within the same event are assigned the same lane.
-      setCurrentEventTransitionLane(claimNextTransitionLane());
+      currentEventTransitionLane = claimNextTransitionLane();
     }
-    return getCurrentEventTransitionLane();
+    return currentEventTransitionLane;
   }
 
   // Updates originating inside certain React methods, like flushSync, have
@@ -848,6 +848,8 @@ export function performConcurrentWorkOnRoot(
     resetNestedUpdateFlag();
   }
 
+  currentEventTransitionLane = NoLanes;
+
   if ((executionContext & (RenderContext | CommitContext)) !== NoContext) {
     throw new Error('Should not already be working.');
   }

packages/react-reconciler/src/__tests__/ReactFiberHostContext-test.internal.js

@@ -70,9 +70,6 @@ describe('ReactFiberHostContext', () => {
       getCurrentEventPriority: function () {
         return DefaultEventPriority;
       },
-      shouldAttemptEagerTransition() {
-        return false;
-      },
       requestPostPaintCallback: function () {},
       maySuspendCommit(type, props) {
         return false;

packages/react-reconciler/src/forks/ReactFiberConfig.custom.js

@@ -66,8 +66,6 @@ export const preparePortalMount = $$$config.preparePortalMount;
 export const prepareScopeUpdate = $$$config.prepareScopeUpdate;
 export const getInstanceFromScope = $$$config.getInstanceFromScope;
 export const getCurrentEventPriority = $$$config.getCurrentEventPriority;
-export const shouldAttemptEagerTransition =
-  $$$config.shouldAttemptEagerTransition;
 export const detachDeletedInstance = $$$config.detachDeletedInstance;
 export const requestPostPaintCallback = $$$config.requestPostPaintCallback;
 export const maySuspendCommit = $$$config.maySuspendCommit;