Remove onScroll bubbling flag (#19535)

Author: gaearon

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

@@ -712,23 +712,12 @@ describe('ReactDOMEventListener', () => {
           bubbles: false,
         }),
       );
-      if (gate(flags => flags.disableOnScrollBubbling)) {
-        expect(log).toEqual([
-          ['capture', 'grand'],
-          ['capture', 'parent'],
-          ['capture', 'child'],
-          ['bubble', 'child'],
-        ]);
-      } else {
-        expect(log).toEqual([
-          ['capture', 'grand'],
-          ['capture', 'parent'],
-          ['capture', 'child'],
-          ['bubble', 'child'],
-          ['bubble', 'parent'],
-          ['bubble', 'grand'],
-        ]);
-      }
+      expect(log).toEqual([
+        ['capture', 'grand'],
+        ['capture', 'parent'],
+        ['capture', 'child'],
+        ['bubble', 'child'],
+      ]);
     } finally {
       document.body.removeChild(container);
     }

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

@@ -1154,12 +1154,6 @@ describe('ReactDOMEventListener', () => {
   });
 
   describe('non-bubbling events that do not bubble in React', () => {
-    // This test will fail outside of the no-bubbling flag
-    // because its bubbling emulation is currently broken.
-    // In particular, if the target itself doesn't have
-    // a handler, it will not emulate bubbling correctly.
-    // Instead of fixing this, we'll just turn this flag on.
-    // @gate disableOnScrollBubbling
     it('onScroll', () => {
       testNonBubblingEvent({
         type: 'div',

packages/react-dom/src/events/plugins/SimpleEventPlugin.js

@@ -47,10 +47,7 @@ import {IS_EVENT_HANDLE_NON_MANAGED_NODE} from '../EventSystemFlags';
 import getEventCharCode from '../getEventCharCode';
 import {IS_CAPTURE_PHASE} from '../EventSystemFlags';
 
-import {
-  enableCreateEventHandleAPI,
-  disableOnScrollBubbling,
-} from 'shared/ReactFeatureFlags';
+import {enableCreateEventHandleAPI} from 'shared/ReactFeatureFlags';
 
 function extractEvents(
   dispatchQueue: DispatchQueue,
@@ -177,15 +174,13 @@ function extractEvents(
     // In the past, React has always bubbled them, but this can be surprising.
     // We're going to try aligning closer to the browser behavior by not bubbling
     // them in React either. We'll start by not bubbling onScroll, and then expand.
-    let accumulateTargetOnly = false;
-    if (disableOnScrollBubbling) {
-      accumulateTargetOnly =
-        !inCapturePhase &&
-        // TODO: ideally, we'd eventually add all events from
-        // nonDelegatedEvents list in DOMPluginEventSystem.
-        // Then we can remove this special list.
-        domEventName === 'scroll';
-    }
+    const accumulateTargetOnly =
+      !inCapturePhase &&
+      // TODO: ideally, we'd eventually add all events from
+      // nonDelegatedEvents list in DOMPluginEventSystem.
+      // Then we can remove this special list.
+      // This is a breaking change that can wait until React 18.
+      domEventName === 'scroll';
 
     accumulateSinglePhaseListeners(
       targetInst,

packages/shared/ReactFeatureFlags.js

@@ -125,5 +125,3 @@ export const deferRenderPhaseUpdateToNextBatch = true;
 
 // Replacement for runWithPriority in React internals.
 export const decoupleUpdatePriorityFromScheduler = false;
-
-export const disableOnScrollBubbling = true;

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

@@ -44,7 +44,6 @@ export const warnAboutSpreadingKeyToJSX = false;
 export const enableComponentStackLocations = false;
 export const enableLegacyFBSupport = false;
 export const enableFilterEmptyStringAttributesDOM = false;
-export const disableOnScrollBubbling = true;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;

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

@@ -43,7 +43,6 @@ export const warnAboutSpreadingKeyToJSX = false;
 export const enableComponentStackLocations = false;
 export const enableLegacyFBSupport = false;
 export const enableFilterEmptyStringAttributesDOM = false;
-export const disableOnScrollBubbling = true;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;

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

@@ -43,7 +43,6 @@ export const warnAboutSpreadingKeyToJSX = false;
 export const enableComponentStackLocations = true;
 export const enableLegacyFBSupport = false;
 export const enableFilterEmptyStringAttributesDOM = false;
-export const disableOnScrollBubbling = true;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;

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

@@ -43,7 +43,6 @@ export const warnAboutSpreadingKeyToJSX = false;
 export const enableComponentStackLocations = true;
 export const enableLegacyFBSupport = false;
 export const enableFilterEmptyStringAttributesDOM = false;
-export const disableOnScrollBubbling = true;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;

packages/shared/forks/ReactFeatureFlags.testing.js

@@ -43,7 +43,6 @@ export const warnAboutSpreadingKeyToJSX = false;
 export const enableComponentStackLocations = true;
 export const enableLegacyFBSupport = false;
 export const enableFilterEmptyStringAttributesDOM = false;
-export const disableOnScrollBubbling = true;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;

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

@@ -43,7 +43,6 @@ export const warnAboutSpreadingKeyToJSX = false;
 export const enableComponentStackLocations = true;
 export const enableLegacyFBSupport = !__EXPERIMENTAL__;
 export const enableFilterEmptyStringAttributesDOM = false;
-export const disableOnScrollBubbling = true;
 
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = true;