From dc298fdf91b6056b097bce0eb05cfe90b873b158 Mon Sep 17 00:00:00 2001
From: Dominic Gannaway <trueadm@users.noreply.github.com>
Date: Fri, 21 Jun 2019 23:10:55 +0100
Subject: [PATCH] [Flare] Refinements to useEvent hook (#15955)

---
 .../src/events/DOMEventResponderSystem.js     | 64 ++++++++++---------
 .../DOMEventResponderSystem-test.internal.js  | 20 ++++--
 .../src/ReactFiberCompleteWork.js             |  2 +-
 .../react-reconciler/src/ReactFiberEvents.js  | 10 +--
 .../react-reconciler/src/ReactFiberHooks.js   | 24 +++----
 packages/react/src/ReactHooks.js              |  6 +-
 packages/shared/ReactDOMTypes.js              |  1 +
 packages/shared/ReactTypes.js                 |  2 +-
 8 files changed, 73 insertions(+), 56 deletions(-)

diff --git a/packages/react-dom/src/events/DOMEventResponderSystem.js b/packages/react-dom/src/events/DOMEventResponderSystem.js
index 0ba8b75265..eef152b502 100644
--- a/packages/react-dom/src/events/DOMEventResponderSystem.js
+++ b/packages/react-dom/src/events/DOMEventResponderSystem.js
@@ -84,6 +84,7 @@ type ResponderTimeout = {|
 |};
 
 type ResponderTimer = {|
+  isHook: boolean,
   instance: ReactDOMEventComponentInstance,
   func: () => void,
   id: number,
@@ -117,6 +118,7 @@ let currentInstance: null | ReactDOMEventComponentInstance = null;
 let currentEventQueue: null | EventQueue = null;
 let currentTimerIDCounter = 0;
 let currentDocument: null | Document = null;
+let currentlyInHook = false;
 
 const eventResponderContext: ReactDOMResponderContext = {
   dispatchEvent(
@@ -366,6 +368,7 @@ const eventResponderContext: ReactDOMResponderContext = {
       currentTimers.set(delay, timeout);
     }
     timeout.timers.set(timerId, {
+      isHook: currentlyInHook,
       instance: ((currentInstance: any): ReactDOMEventComponentInstance),
       func,
       id: timerId,
@@ -456,6 +459,9 @@ const eventResponderContext: ReactDOMResponderContext = {
     validateResponderContext();
     continueLocalPropagation = true;
   },
+  isRespondingToHook() {
+    return currentlyInHook;
+  },
 };
 
 function collectFocusableElements(
@@ -535,9 +541,10 @@ function processTimers(
   currentEventQueue = createEventQueue();
   try {
     for (let i = 0; i < timersArr.length; i++) {
-      const {instance, func, id, timeStamp} = timersArr[i];
+      const {isHook, instance, func, id, timeStamp} = timersArr[i];
       currentInstance = instance;
       currentTimeStamp = timeStamp + delay;
+      currentlyInHook = isHook;
       try {
         func();
       } finally {
@@ -763,9 +770,9 @@ function shouldSkipEventComponent(
   eventResponderInstance: ReactDOMEventComponentInstance,
   responder: ReactDOMEventResponder,
   propagatedEventResponders: null | Set<ReactDOMEventResponder>,
-  localPropagation: boolean,
+  isHook: boolean,
 ): boolean {
-  if (propagatedEventResponders !== null && localPropagation) {
+  if (propagatedEventResponders !== null && !isHook) {
     if (propagatedEventResponders.has(responder)) {
       return true;
     }
@@ -830,12 +837,7 @@ function traverseAndHandleEventResponderInstances(
     // Capture target phase
     for (i = length; i-- > 0; ) {
       const targetEventResponderInstance = targetEventResponderInstances[i];
-      const {
-        localPropagation,
-        props,
-        responder,
-        state,
-      } = targetEventResponderInstance;
+      const {isHook, props, responder, state} = targetEventResponderInstance;
       const eventListener = responder.onEventCapture;
       if (eventListener !== undefined) {
         if (
@@ -843,14 +845,15 @@ function traverseAndHandleEventResponderInstances(
             targetEventResponderInstance,
             ((responder: any): ReactDOMEventResponder),
             propagatedEventResponders,
-            localPropagation,
+            isHook,
           )
         ) {
           continue;
         }
         currentInstance = targetEventResponderInstance;
+        currentlyInHook = isHook;
         eventListener(responderEvent, eventResponderContext, props, state);
-        if (localPropagation) {
+        if (!isHook) {
           checkForLocalPropagationContinuation(
             responder,
             propagatedEventResponders,
@@ -863,12 +866,7 @@ function traverseAndHandleEventResponderInstances(
     // Bubble target phase
     for (i = 0; i < length; i++) {
       const targetEventResponderInstance = targetEventResponderInstances[i];
-      const {
-        localPropagation,
-        props,
-        responder,
-        state,
-      } = targetEventResponderInstance;
+      const {isHook, props, responder, state} = targetEventResponderInstance;
       const eventListener = responder.onEvent;
       if (eventListener !== undefined) {
         if (
@@ -876,14 +874,15 @@ function traverseAndHandleEventResponderInstances(
             targetEventResponderInstance,
             ((responder: any): ReactDOMEventResponder),
             propagatedEventResponders,
-            localPropagation,
+            isHook,
           )
         ) {
           continue;
         }
         currentInstance = targetEventResponderInstance;
+        currentlyInHook = isHook;
         eventListener(responderEvent, eventResponderContext, props, state);
-        if (localPropagation) {
+        if (!isHook) {
           checkForLocalPropagationContinuation(
             responder,
             propagatedEventResponders,
@@ -900,12 +899,7 @@ function traverseAndHandleEventResponderInstances(
   if (length > 0) {
     for (i = 0; i < length; i++) {
       const rootEventResponderInstance = rootEventResponderInstances[i];
-      const {
-        localPropagation,
-        props,
-        responder,
-        state,
-      } = rootEventResponderInstance;
+      const {isHook, props, responder, state} = rootEventResponderInstance;
       const eventListener = responder.onRootEvent;
       if (eventListener !== undefined) {
         if (
@@ -913,12 +907,13 @@ function traverseAndHandleEventResponderInstances(
             rootEventResponderInstance,
             responder,
             null,
-            localPropagation,
+            isHook,
           )
         ) {
           continue;
         }
         currentInstance = rootEventResponderInstance;
+        currentlyInHook = isHook;
         eventListener(responderEvent, eventResponderContext, props, state);
       }
     }
@@ -928,19 +923,24 @@ function traverseAndHandleEventResponderInstances(
 function triggerOwnershipListeners(): void {
   const listeningInstances = Array.from(ownershipChangeListeners);
   const previousInstance = currentInstance;
+  const previouslyInHook = currentlyInHook;
+  currentEventQueue = createEventQueue();
   try {
     for (let i = 0; i < listeningInstances.length; i++) {
       const instance = listeningInstances[i];
-      const {props, responder, state} = instance;
+      const {isHook, props, responder, state} = instance;
       currentInstance = instance;
+      currentlyInHook = isHook;
       const onOwnershipChange = ((responder: any): ReactDOMEventResponder)
         .onOwnershipChange;
       if (onOwnershipChange !== undefined) {
         onOwnershipChange(eventResponderContext, props, state);
       }
     }
+    processEventQueue();
   } finally {
     currentInstance = previousInstance;
+    currentlyInHook = previouslyInHook;
   }
 }
 
@@ -953,11 +953,13 @@ export function mountEventResponder(
   }
   const onMount = responder.onMount;
   if (onMount !== undefined) {
-    let {props, state} = eventComponentInstance;
+    let {isHook, props, state} = eventComponentInstance;
     currentEventQueue = createEventQueue();
     currentInstance = eventComponentInstance;
+    currentlyInHook = isHook;
     try {
       onMount(eventResponderContext, props, state);
+      processEventQueue();
     } finally {
       currentEventQueue = null;
       currentInstance = null;
@@ -972,11 +974,13 @@ export function unmountEventResponder(
   const responder = ((eventComponentInstance.responder: any): ReactDOMEventResponder);
   const onUnmount = responder.onUnmount;
   if (onUnmount !== undefined) {
-    let {props, state} = eventComponentInstance;
+    let {isHook, props, state} = eventComponentInstance;
     currentEventQueue = createEventQueue();
     currentInstance = eventComponentInstance;
+    currentlyInHook = isHook;
     try {
       onUnmount(eventResponderContext, props, state);
+      processEventQueue();
     } finally {
       currentEventQueue = null;
       currentInstance = null;
@@ -1030,6 +1034,7 @@ export function dispatchEventForResponderEventSystem(
     const previousTimers = currentTimers;
     const previousTimeStamp = currentTimeStamp;
     const previousDocument = currentDocument;
+    const previouslyInHook = currentlyInHook;
     currentTimers = null;
     currentEventQueue = createEventQueue();
     currentDocument = (nativeEventTarget: any).ownerDocument;
@@ -1050,6 +1055,7 @@ export function dispatchEventForResponderEventSystem(
       currentEventQueue = previousEventQueue;
       currentTimeStamp = previousTimeStamp;
       currentDocument = previousDocument;
+      currentlyInHook = previouslyInHook;
     }
   }
 }
diff --git a/packages/react-dom/src/events/__tests__/DOMEventResponderSystem-test.internal.js b/packages/react-dom/src/events/__tests__/DOMEventResponderSystem-test.internal.js
index edd849fb71..7270647780 100644
--- a/packages/react-dom/src/events/__tests__/DOMEventResponderSystem-test.internal.js
+++ b/packages/react-dom/src/events/__tests__/DOMEventResponderSystem-test.internal.js
@@ -1067,11 +1067,12 @@ describe('DOMEventResponderSystem', () => {
           };
           context.dispatchEvent(fooEvent, props.onFoo, DiscreteEvent);
         }
+        eventLogs.push(context.isRespondingToHook() ? '[hook]' : '[component]');
       },
     });
 
     const Test = () => {
-      React.unstable_useEvent(EventComponent.responder, {
+      React.unstable_useEvent(EventComponent, {
         onFoo: e => eventLogs.push('hook'),
       });
       return (
@@ -1083,13 +1084,13 @@ describe('DOMEventResponderSystem', () => {
 
     ReactDOM.render(<Test />, container);
     buttonRef.current.dispatchEvent(createEvent('foo'));
-    expect(eventLogs).toEqual(['prop', 'hook']);
+    expect(eventLogs).toEqual(['[component]', '[hook]', 'prop', 'hook']);
 
     // Clear events
     eventLogs.length = 0;
 
     const Test2 = () => {
-      React.unstable_useEvent(EventComponent.responder, {
+      React.unstable_useEvent(EventComponent, {
         onFoo: e => eventLogs.push('hook'),
       });
       return <button ref={buttonRef} />;
@@ -1101,10 +1102,10 @@ describe('DOMEventResponderSystem', () => {
     expect(eventLogs).toEqual([]);
 
     const Test3 = () => {
-      React.unstable_useEvent(EventComponent.responder, {
+      React.unstable_useEvent(EventComponent, {
         onFoo: e => eventLogs.push('hook 2a'),
       });
-      React.unstable_useEvent(EventComponent.responder, {
+      React.unstable_useEvent(EventComponent, {
         onFoo: e => eventLogs.push('hook 2b'),
       });
       return (
@@ -1118,6 +1119,13 @@ describe('DOMEventResponderSystem', () => {
 
     ReactDOM.render(<Test3 />, container);
     buttonRef.current.dispatchEvent(createEvent('foo'));
-    expect(eventLogs).toEqual(['prop 2', 'hook 2a', 'hook 2b']);
+    expect(eventLogs).toEqual([
+      '[component]',
+      '[hook]',
+      '[hook]',
+      'prop 2',
+      'hook 2a',
+      'hook 2b',
+    ]);
   });
 });
diff --git a/packages/react-reconciler/src/ReactFiberCompleteWork.js b/packages/react-reconciler/src/ReactFiberCompleteWork.js
index 5f7cef164b..97f4c227f9 100644
--- a/packages/react-reconciler/src/ReactFiberCompleteWork.js
+++ b/packages/react-reconciler/src/ReactFiberCompleteWork.js
@@ -1041,7 +1041,7 @@ function completeWork(
             responder,
             rootContainerInstance,
             responderState || {},
-            true,
+            false,
           );
           markUpdate(workInProgress);
         } else {
diff --git a/packages/react-reconciler/src/ReactFiberEvents.js b/packages/react-reconciler/src/ReactFiberEvents.js
index c9c35f0477..f809bb3343 100644
--- a/packages/react-reconciler/src/ReactFiberEvents.js
+++ b/packages/react-reconciler/src/ReactFiberEvents.js
@@ -9,6 +9,7 @@
 
 import type {Fiber, Dependencies} from './ReactFiber';
 import type {
+  ReactEventComponent,
   ReactEventResponder,
   ReactEventComponentInstance,
 } from 'shared/ReactTypes';
@@ -32,9 +33,10 @@ export function prepareToReadEventComponents(workInProgress: Fiber): void {
 }
 
 export function updateEventComponentInstance<T, E, C>(
-  responder: ReactEventResponder<T, E, C>,
+  eventComponent: ReactEventComponent<T, E, C>,
   props: Object,
 ): void {
+  const responder = eventComponent.responder;
   invariant(
     responder.allowEventHooks,
     'The "%s" event responder cannot be used via the "useEvent" hook.',
@@ -67,7 +69,7 @@ export function updateEventComponentInstance<T, E, C>(
       responder,
       null,
       responderState || {},
-      false,
+      true,
     );
     events.push(eventComponentInstance);
     currentEventComponentInstanceIndex++;
@@ -85,11 +87,11 @@ export function createEventComponentInstance<T, E, C>(
   responder: ReactEventResponder<T, E, C>,
   rootInstance: mixed,
   state: Object,
-  localPropagation: boolean,
+  isHook: boolean,
 ): ReactEventComponentInstance<T, E, C> {
   return {
     currentFiber,
-    localPropagation,
+    isHook,
     props,
     responder,
     rootEventTypes: null,
diff --git a/packages/react-reconciler/src/ReactFiberHooks.js b/packages/react-reconciler/src/ReactFiberHooks.js
index 7f9372bdc7..bbec37ceee 100644
--- a/packages/react-reconciler/src/ReactFiberHooks.js
+++ b/packages/react-reconciler/src/ReactFiberHooks.js
@@ -7,7 +7,7 @@
  * @flow
  */
 
-import type {ReactEventResponder, ReactContext} from 'shared/ReactTypes';
+import type {ReactEventComponent, ReactContext} from 'shared/ReactTypes';
 import type {SideEffectTag} from 'shared/ReactSideEffectTags';
 import type {Fiber} from './ReactFiber';
 import type {ExpirationTime} from './ReactFiberExpirationTime';
@@ -83,7 +83,7 @@ export type Dispatcher = {
   ): void,
   useDebugValue<T>(value: T, formatterFn: ?(value: T) => mixed): void,
   useEvent<T, E, C>(
-    responder: ReactEventResponder<T, E, C>,
+    eventComponent: ReactEventComponent<T, E, C>,
     props: Object,
   ): void,
 };
@@ -1399,10 +1399,10 @@ if (__DEV__) {
       mountHookTypesDev();
       return mountDebugValue(value, formatterFn);
     },
-    useEvent<T, E, C>(responder: ReactEventResponder<T, E, C>, props) {
+    useEvent<T, E, C>(eventComponent: ReactEventComponent<T, E, C>, props) {
       currentHookNameInDev = 'useEvent';
       mountHookTypesDev();
-      updateEventComponentInstance(responder, props);
+      updateEventComponentInstance(eventComponent, props);
     },
   };
 
@@ -1501,10 +1501,10 @@ if (__DEV__) {
       updateHookTypesDev();
       return mountDebugValue(value, formatterFn);
     },
-    useEvent<T, E, C>(responder: ReactEventResponder<T, E, C>, props) {
+    useEvent<T, E, C>(eventComponent: ReactEventComponent<T, E, C>, props) {
       currentHookNameInDev = 'useEvent';
       updateHookTypesDev();
-      updateEventComponentInstance(responder, props);
+      updateEventComponentInstance(eventComponent, props);
     },
   };
 
@@ -1603,10 +1603,10 @@ if (__DEV__) {
       updateHookTypesDev();
       return updateDebugValue(value, formatterFn);
     },
-    useEvent<T, E, C>(responder: ReactEventResponder<T, E, C>, props) {
+    useEvent<T, E, C>(eventComponent: ReactEventComponent<T, E, C>, props) {
       currentHookNameInDev = 'useEvent';
       updateHookTypesDev();
-      updateEventComponentInstance(responder, props);
+      updateEventComponentInstance(eventComponent, props);
     },
   };
 
@@ -1716,11 +1716,11 @@ if (__DEV__) {
       mountHookTypesDev();
       return mountDebugValue(value, formatterFn);
     },
-    useEvent<T, E, C>(responder: ReactEventResponder<T, E, C>, props) {
+    useEvent<T, E, C>(eventComponent: ReactEventComponent<T, E, C>, props) {
       currentHookNameInDev = 'useEvent';
       warnInvalidHookAccess();
       mountHookTypesDev();
-      updateEventComponentInstance(responder, props);
+      updateEventComponentInstance(eventComponent, props);
     },
   };
 
@@ -1830,11 +1830,11 @@ if (__DEV__) {
       updateHookTypesDev();
       return updateDebugValue(value, formatterFn);
     },
-    useEvent<T, E, C>(responder: ReactEventResponder<T, E, C>, props) {
+    useEvent<T, E, C>(eventComponent: ReactEventComponent<T, E, C>, props) {
       currentHookNameInDev = 'useEvent';
       warnInvalidHookAccess();
       updateHookTypesDev();
-      updateEventComponentInstance(responder, props);
+      updateEventComponentInstance(eventComponent, props);
     },
   };
 }
diff --git a/packages/react/src/ReactHooks.js b/packages/react/src/ReactHooks.js
index 55da95160a..1f67171598 100644
--- a/packages/react/src/ReactHooks.js
+++ b/packages/react/src/ReactHooks.js
@@ -7,7 +7,7 @@
  * @flow
  */
 
-import type {ReactEventResponder, ReactContext} from 'shared/ReactTypes';
+import type {ReactEventComponent, ReactContext} from 'shared/ReactTypes';
 import invariant from 'shared/invariant';
 import warning from 'shared/warning';
 
@@ -139,9 +139,9 @@ export function useDebugValue(value: any, formatterFn: ?(value: any) => any) {
 export const emptyObject = {};
 
 export function useEvent<T, E, C>(
-  responder: ReactEventResponder<T, E, C>,
+  eventComponent: ReactEventComponent<T, E, C>,
   props: null | Object,
 ) {
   const dispatcher = resolveDispatcher();
-  return dispatcher.useEvent(responder, props || emptyObject);
+  return dispatcher.useEvent(eventComponent, props || emptyObject);
 }
diff --git a/packages/shared/ReactDOMTypes.js b/packages/shared/ReactDOMTypes.js
index d5612c5503..920e6ec171 100644
--- a/packages/shared/ReactDOMTypes.js
+++ b/packages/shared/ReactDOMTypes.js
@@ -84,4 +84,5 @@ export type ReactDOMResponderContext = {
     deep: boolean,
   ) => boolean,
   continueLocalPropagation(): void,
+  isRespondingToHook(): boolean,
 };
diff --git a/packages/shared/ReactTypes.js b/packages/shared/ReactTypes.js
index f74111ab0e..02bc0e7fbe 100644
--- a/packages/shared/ReactTypes.js
+++ b/packages/shared/ReactTypes.js
@@ -83,7 +83,7 @@ export type RefObject = {|
 
 export type ReactEventComponentInstance<T, E, C> = {|
   currentFiber: mixed,
-  localPropagation: boolean,
+  isHook: boolean,
   props: Object,
   responder: ReactEventResponder<T, E, C>,
   rootEventTypes: null | Set<string>,