RN: Export EventEmitter in Public API (#55190)

Summary:
Pull Request resolved: #55190

Makes `EventEmitter` (and the related `IEventEmitter` interface type) available as part of React Native's Public API.

This allows product logic using React Native to also leverage the same abstraction. Currently, code outside of React Native that wants to use `EventEmitter` must resort to deep imports (which is discouraged).

Changelog:
[General][Added] - Added `EventEmitter` to `react-native` exports.

Reviewed By: huntie

Differential Revision: D90786781

fbshipit-source-id: ad06124c96fcba35b8b5fc8170bfb15c17884a0a

Author: yungsters

packages/react-native/ReactNativeApi.d.ts

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<9504863966549f8efbbe4e13d7f74eaf>>
+ * @generated SignedSource<<532b4c9c3a1d7ea9cbfce8c8e8ff3d87>>
  *
  * This file was generated by scripts/js-api/build-types/index.js.
  */
@@ -1865,7 +1865,7 @@ declare namespace CodegenTypes {
     UnsafeMixed,
     DefaultTypes,
     WithDefault,
-    EventEmitter,
+    EventEmitter_2 as EventEmitter,
   }
 }
 declare type ColorListenerCallback = (value: ColorValue) => unknown
@@ -2229,7 +2229,28 @@ declare type EventConfig<T> = {
   platformConfig?: PlatformConfig
   useNativeDriver: boolean
 }
-declare type EventEmitter<T> = (
+declare class EventEmitter<
+  TEventToArgsMap extends Readonly<
+    Record<string, ReadonlyArray<UnsafeEventObject>>
+  > = Readonly<Record<string, ReadonlyArray<UnsafeEventObject>>>,
+> implements IEventEmitter<TEventToArgsMap>
+{
+  addListener<TEvent extends keyof TEventToArgsMap>(
+    eventType: TEvent,
+    listener: (...args: TEventToArgsMap[TEvent]) => unknown,
+    context: unknown,
+  ): EventSubscription
+  constructor()
+  emit<TEvent extends keyof TEventToArgsMap>(
+    eventType: TEvent,
+    ...args: TEventToArgsMap[TEvent]
+  ): void
+  listenerCount<TEvent extends keyof TEventToArgsMap>(eventType: TEvent): number
+  removeAllListeners<TEvent extends keyof TEventToArgsMap>(
+    eventType?: null | TEvent | undefined,
+  ): void
+}
+declare type EventEmitter_2<T> = (
   handler: ($$PARAM_0$$: T) => Promise<void> | void,
 ) => EventSubscription
 declare type EventName = (() => string) | string
@@ -5988,15 +6009,15 @@ export {
   Button, // ef82aed4
   ButtonProps, // 3c081e75
   Clipboard, // 41addb89
-  CodegenTypes, // 030a94b8
+  CodegenTypes, // adbc477c
   ColorSchemeName, // 31a4350e
   ColorValue, // 98989a8f
   ComponentProvider, // b5c60ddd
   ComponentProviderInstrumentationHook, // 9f640048
   CursorValue, // 26522595
   DevMenu, // 21b8b7a9
   DevSettings, // e55b91dc
-  DeviceEventEmitter, // 650e6394
+  DeviceEventEmitter, // bdbdd014
   DeviceInfo, // 521bfb71
   DeviceInfoConstants, // 279e7858
   DimensionValue, // b163a381
@@ -6016,6 +6037,7 @@ export {
   EmitterSubscription, // de50c359
   EnterKeyHintTypeOptions, // 8314de78
   ErrorUtils, // 38fb909e
+  EventEmitter, // 2a2ea995
   EventSubscription, // b8d084aa
   ExtendedExceptionData, // 5a6ccf5a
   FilterFunction, // bf24c0e3
@@ -6029,6 +6051,7 @@ export {
   HostComponent, // 5e13ff5a
   HostInstance, // 489cbe7f
   I18nManager, // f9870e00
+  IEventEmitter, // fbef6131
   IOSKeyboardEvent, // e67bfe3a
   IgnorePattern, // ec6f6ece
   Image, // 957b3726
@@ -6074,7 +6097,7 @@ export {
   LayoutChangeEvent, // c674f902
   LayoutConformanceProps, // 055f03b8
   LayoutRectangle, // 6601b294
-  Linking, // b5645d2b
+  Linking, // 9a6a174d
   ListRenderItem, // b5353fd8
   ListRenderItemInfo, // e8595b03
   ListViewToken, // 833d3481
@@ -6090,11 +6113,11 @@ export {
   ModalPropsIOS, // 4fbcedf6
   ModeChangeEvent, // 16790307
   MouseEvent, // 53ede3db
-  NativeAppEventEmitter, // e1340a0a
+  NativeAppEventEmitter, // 08d4c47d
   NativeColorValue, // d2094c29
   NativeComponentRegistry, // 7fd99ba6
   NativeDialogManagerAndroid, // 5be8497e
-  NativeEventEmitter, // d72906cc
+  NativeEventEmitter, // 27f97c1a
   NativeEventSubscription, // de3942e7
   NativeMethods, // 03dc51c5
   NativeMethodsMixin, // 4b061b7e

packages/react-native/index.js

@@ -42,6 +42,9 @@ module.exports = {
     return require('./Libraries/Components/DrawerAndroid/DrawerLayoutAndroid')
       .default;
   },
+  get EventEmitter() {
+    return require('./Libraries/vendor/emitter/EventEmitter').default;
+  },
   get FlatList() {
     return require('./Libraries/Lists/FlatList').default;
   },

packages/react-native/index.js.flow

@@ -320,7 +320,6 @@ export * as NativeComponentRegistry from './Libraries/NativeComponent/NativeComp
 export {default as NativeDialogManagerAndroid} from './Libraries/NativeModules/specs/NativeDialogManagerAndroid';
 
 export type {
-  EventSubscription,
   EmitterSubscription,
   NativeEventSubscription,
 } from './Libraries/EventEmitter/NativeEventEmitter';
@@ -463,6 +462,12 @@ export type {
   PublicTextInstance,
 } from './Libraries/ReactPrivate/ReactNativePrivateInterface';
 
+export type {
+  EventSubscription,
+  IEventEmitter,
+} from './Libraries/vendor/emitter/EventEmitter';
+export {default as EventEmitter} from './Libraries/vendor/emitter/EventEmitter';
+
 export {
   default as unstable_VirtualView,
   VirtualViewMode,