Remove unnecessary Event and CustomEvent polyfills (#50495)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/50495

Changelog: [internal]

This migrates the last remaining usages of these polyfills to the built-in classes.

Reviewed By: yungsters

Differential Revision: D67828652

fbshipit-source-id: 5ff039d7413aed49d882ff03e722531cdd195488

packages/react-native/Libraries/Events/CustomEvent.js

@@ -1,32 +0,0 @@
-/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- *
- * @format
- * @flow strict-local
- */
-
-// Make sure global Event is defined
-import EventPolyfill from './EventPolyfill';
-
-type CustomEvent$Options = $ReadOnly<{
-  bubbles?: boolean,
-  cancelable?: boolean,
-  composed?: boolean,
-  detail?: {...},
-}>;
-
-class CustomEvent extends EventPolyfill {
-  detail: ?{...};
-
-  constructor(typeArg: string, options: CustomEvent$Options) {
-    const {bubbles, cancelable, composed} = options;
-    super(typeArg, {bubbles, cancelable, composed});
-
-    this.detail = options.detail; // this would correspond to `NativeEvent` in NativeSyntheticEvent
-  }
-}
-
-export default CustomEvent;

packages/react-native/Libraries/Events/EventPolyfill.js

@@ -1,239 +0,0 @@
-/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- *
- * @format
- * @flow strict-local
- */
-
-// https://dom.spec.whatwg.org/#dictdef-eventinit
-type Event$Init = {
-  bubbles?: boolean,
-  cancelable?: boolean,
-  composed?: boolean,
-  /** Non-standard. See `composed` instead. */
-  scoped?: boolean,
-  ...
-};
-
-/**
- * This is a copy of the Event interface defined in Flow:
- * https://github.com/facebook/flow/blob/741104e69c43057ebd32804dd6bcc1b5e97548ea/lib/dom.js
- * which is itself a faithful interface of the W3 spec:
- * https://dom.spec.whatwg.org/#interface-event
- *
- * Since Flow assumes that Event is provided and is on the global object,
- * we must provide an implementation of Event for CustomEvent (and future
- * alignment of React Native's event system with the W3 spec).
- */
-interface IEvent {
-  constructor(type: string, eventInitDict?: Event$Init): void;
-  /**
-   * Returns the type of event, e.g. "click", "hashchange", or "submit".
-   */
-  +type: string;
-  /**
-   * Returns the object to which event is dispatched (its target).
-   */
-  +target: EventTarget; // TODO: nullable
-  /** @deprecated */
-  +srcElement: Element; // TODO: nullable
-  /**
-   * Returns the object whose event listener's callback is currently being invoked.
-   */
-  +currentTarget: EventTarget; // TODO: nullable
-  /**
-   * Returns the invocation target objects of event's path (objects on which
-   * listeners will be invoked), except for any nodes in shadow trees of which
-   * the shadow root's mode is "closed" that are not reachable from event's
-   * currentTarget.
-   */
-  composedPath(): Array<EventTarget>;
-
-  +NONE: number;
-  +AT_TARGET: number;
-  +BUBBLING_PHASE: number;
-  +CAPTURING_PHASE: number;
-  /**
-   * Returns the event's phase, which is one of NONE, CAPTURING_PHASE, AT_TARGET,
-   * and BUBBLING_PHASE.
-   */
-  +eventPhase: number;
-
-  /**
-   * When dispatched in a tree, invoking this method prevents event from reaching
-   * any objects other than the current object.
-   */
-  stopPropagation(): void;
-  /**
-   * Invoking this method prevents event from reaching any registered event
-   * listeners after the current one finishes running and, when dispatched in a
-   * tree, also prevents event from reaching any other objects.
-   */
-  stopImmediatePropagation(): void;
-
-  /**
-   * Returns true or false depending on how event was initialized. True if
-   * event goes through its target's ancestors in reverse tree order, and
-   * false otherwise.
-   */
-  +bubbles: boolean;
-  /**
-   * Returns true or false depending on how event was initialized. Its
-   * return value does not always carry meaning, but true can indicate
-   * that part of the operation during which event was dispatched, can
-   * be canceled by invoking the preventDefault() method.
-   */
-  +cancelable: boolean;
-  // returnValue: boolean; // legacy, and some subclasses still define it as a string!
-  /**
-   * If invoked when the cancelable attribute value is true, and while
-   * executing a listener for the event with passive set to false, signals to
-   * the operation that caused event to be dispatched that it needs to be
-   * canceled.
-   */
-  preventDefault(): void;
-  /**
-   * Returns true if preventDefault() was invoked successfully to indicate
-   * cancelation, and false otherwise.
-   */
-  +defaultPrevented: boolean;
-  /**
-   * Returns true or false depending on how event was initialized. True if
-   * event invokes listeners past a ShadowRoot node that is the root of its
-   * target, and false otherwise.
-   */
-  +composed: boolean;
-
-  /**
-   * Returns true if event was dispatched by the user agent, and false otherwise.
-   */
-  +isTrusted: boolean;
-  /**
-   * Returns the event's timestamp as the number of milliseconds measured relative
-   * to the time origin.
-   */
-  +timeStamp: number;
-
-  /** Non-standard. See Event.prototype.composedPath */
-  +deepPath?: () => EventTarget[];
-  /** Non-standard. See Event.prototype.composed */
-  +scoped: boolean;
-
-  /**
-   * @deprecated
-   */
-  initEvent(type: string, bubbles: boolean, cancelable: boolean): void;
-}
-
-class EventPolyfill implements IEvent {
-  type: string;
-  bubbles: boolean;
-  cancelable: boolean;
-  composed: boolean;
-  // Non-standard. See `composed` instead.
-  scoped: boolean;
-  isTrusted: boolean;
-  defaultPrevented: boolean;
-  timeStamp: number;
-
-  // https://developer.mozilla.org/en-US/docs/Web/API/Event/eventPhase
-  NONE: number;
-  AT_TARGET: number;
-  BUBBLING_PHASE: number;
-  CAPTURING_PHASE: number;
-
-  eventPhase: number;
-
-  currentTarget: EventTarget; // TODO: nullable
-  target: EventTarget; // TODO: nullable
-  /** @deprecated */
-  srcElement: Element; // TODO: nullable
-
-  // React Native-specific: proxy data to a NativeSyntheticEvent when
-  // certain methods are called.
-  // NativeSyntheticEvent will also have a reference to this instance -
-  // it is circular - and both classes use this reference to keep
-  // data with the other in sync.
-  _syntheticEvent: mixed;
-
-  constructor(type: string, eventInitDict?: Event$Init) {
-    this.type = type;
-    this.bubbles = !!(eventInitDict?.bubbles || false);
-    this.cancelable = !!(eventInitDict?.cancelable || false);
-    this.composed = !!(eventInitDict?.composed || false);
-    this.scoped = !!(eventInitDict?.scoped || false);
-
-    // TODO: somehow guarantee that only "private" instantiations of Event
-    // can set this to true
-    this.isTrusted = false;
-
-    // TODO: in the future we'll want to make sure this has the same
-    // time-basis as events originating from native
-    this.timeStamp = Date.now();
-
-    this.defaultPrevented = false;
-
-    // https://developer.mozilla.org/en-US/docs/Web/API/Event/eventPhase
-    this.NONE = 0;
-    this.AT_TARGET = 1;
-    this.BUBBLING_PHASE = 2;
-    this.CAPTURING_PHASE = 3;
-    this.eventPhase = this.NONE;
-
-    // $FlowFixMe
-    this.currentTarget = null;
-    // $FlowFixMe
-    this.target = null;
-    // $FlowFixMe
-    this.srcElement = null;
-  }
-
-  composedPath(): Array<EventTarget> {
-    throw new Error('TODO: not yet implemented');
-  }
-
-  preventDefault(): void {
-    this.defaultPrevented = true;
-
-    if (this._syntheticEvent != null) {
-      // $FlowFixMe
-      this._syntheticEvent.preventDefault();
-    }
-  }
-
-  initEvent(type: string, bubbles: boolean, cancelable: boolean): void {
-    throw new Error(
-      'TODO: not yet implemented. This method is also deprecated.',
-    );
-  }
-
-  stopImmediatePropagation(): void {
-    throw new Error('TODO: not yet implemented');
-  }
-
-  stopPropagation(): void {
-    if (this._syntheticEvent != null) {
-      // $FlowFixMe
-      this._syntheticEvent.stopPropagation();
-    }
-  }
-
-  setSyntheticEvent(value: mixed): void {
-    this._syntheticEvent = value;
-  }
-}
-
-// Assertion magic for polyfill follows.
-declare var checkEvent: Event; // eslint-disable-line no-unused-vars
-
-/*::
-// This can be a strict mode error at runtime so put it in a Flow comment.
-(checkEvent: IEvent);
-*/
-
-global.Event = EventPolyfill;
-
-export default EventPolyfill;

packages/react-native/Libraries/ReactPrivate/ReactNativePrivateInterface.js

@@ -8,6 +8,7 @@
  * @flow strict-local
  */
 
+import typeof CustomEvent from '../../src/private/webapis/dom/events/CustomEvent';
 import typeof BatchedBridge from '../BatchedBridge/BatchedBridge';
 import typeof legacySendAccessibilityEvent from '../Components/AccessibilityInfo/legacySendAccessibilityEvent';
 import typeof TextInputState from '../Components/TextInput/TextInputState';
@@ -15,7 +16,6 @@ import typeof ExceptionsManager from '../Core/ExceptionsManager';
 import typeof RawEventEmitter from '../Core/RawEventEmitter';
 import typeof ReactFiberErrorDialog from '../Core/ReactFiberErrorDialog';
 import typeof RCTEventEmitter from '../EventEmitter/RCTEventEmitter';
-import typeof CustomEvent from '../Events/CustomEvent';
 import typeof {
   createPublicInstance,
   createPublicRootInstance,
@@ -99,7 +99,7 @@ module.exports = {
     return require('../Core/RawEventEmitter').default;
   },
   get CustomEvent(): CustomEvent {
-    return require('../Events/CustomEvent').default;
+    return require('../../src/private/webapis/dom/events/CustomEvent').default;
   },
   get createAttributePayload(): createAttributePayload {
     return require('../ReactNative/ReactFabricPublicInstance/ReactNativeAttributePayload')

packages/react-native/Libraries/__tests__/__snapshots__/public-api-test.js.snap

@@ -4166,83 +4166,6 @@ declare export default typeof RCTNativeAppEventEmitter;
 "
 `;
 
-exports[`public API should not change unintentionally Libraries/Events/CustomEvent.js 1`] = `
-"type CustomEvent$Options = $ReadOnly<{
-  bubbles?: boolean,
-  cancelable?: boolean,
-  composed?: boolean,
-  detail?: { ... },
-}>;
-declare class CustomEvent extends EventPolyfill {
-  detail: ?{ ... };
-  constructor(typeArg: string, options: CustomEvent$Options): void;
-}
-declare export default typeof CustomEvent;
-"
-`;
-
-exports[`public API should not change unintentionally Libraries/Events/EventPolyfill.js 1`] = `
-"type Event$Init = {
-  bubbles?: boolean,
-  cancelable?: boolean,
-  composed?: boolean,
-  scoped?: boolean,
-  ...
-};
-interface IEvent {
-  constructor(type: string, eventInitDict?: Event$Init): void;
-  +type: string;
-  +target: EventTarget;
-  +srcElement: Element;
-  +currentTarget: EventTarget;
-  composedPath(): Array<EventTarget>;
-  +NONE: number;
-  +AT_TARGET: number;
-  +BUBBLING_PHASE: number;
-  +CAPTURING_PHASE: number;
-  +eventPhase: number;
-  stopPropagation(): void;
-  stopImmediatePropagation(): void;
-  +bubbles: boolean;
-  +cancelable: boolean;
-  preventDefault(): void;
-  +defaultPrevented: boolean;
-  +composed: boolean;
-  +isTrusted: boolean;
-  +timeStamp: number;
-  +deepPath?: () => EventTarget[];
-  +scoped: boolean;
-  initEvent(type: string, bubbles: boolean, cancelable: boolean): void;
-}
-declare class EventPolyfill implements IEvent {
-  type: string;
-  bubbles: boolean;
-  cancelable: boolean;
-  composed: boolean;
-  scoped: boolean;
-  isTrusted: boolean;
-  defaultPrevented: boolean;
-  timeStamp: number;
-  NONE: number;
-  AT_TARGET: number;
-  BUBBLING_PHASE: number;
-  CAPTURING_PHASE: number;
-  eventPhase: number;
-  currentTarget: EventTarget;
-  target: EventTarget;
-  srcElement: Element;
-  constructor(type: string, eventInitDict?: Event$Init): void;
-  composedPath(): Array<EventTarget>;
-  preventDefault(): void;
-  initEvent(type: string, bubbles: boolean, cancelable: boolean): void;
-  stopImmediatePropagation(): void;
-  stopPropagation(): void;
-  setSyntheticEvent(value: mixed): void;
-}
-declare export default typeof EventPolyfill;
-"
-`;
-
 exports[`public API should not change unintentionally Libraries/Image/AssetRegistry.js 1`] = `
 "declare const AssetRegistry: {
   registerAsset: (asset: PackagerAsset) => number,