Add flowtype for eventemitter3

Reviewed By: cpojer

Differential Revision: D16459480

fbshipit-source-id: e560be242ef170e407f634638a9a581dbf5dc309

flow-typed/eventemitter3.js.flow

@@ -0,0 +1,29 @@
+// flow-typed signature: b7ab86e40fd87c2d7414d5ceb45ecddb
+// flow-typed version: 6347e0da2b/eventemitter3_v3.x.x/flow_>=v0.25.x
+
+declare module 'eventemitter3' {
+  declare type ListenerFn = (...args: any[]) => mixed
+  declare class EventEmitter {
+    static constructor(): EventEmitter,
+    static prefixed: string | boolean,
+    eventNames(): (string | Symbol)[],
+    listeners(event: string | Symbol): ListenerFn[],
+    listenerCount(event: string | Symbol): number,
+    on(event: string | Symbol, listener: ListenerFn, context?: any): this,
+    addListener(event: string | Symbol, listener: ListenerFn, context?: any): this,
+    once(event: string | Symbol, listener: ListenerFn, context?: any): this,
+    removeAllListeners(event?: string | Symbol): this,
+    removeListener(event: string | Symbol, listener?: ListenerFn, context?: any, once?: boolean): this,
+    off(event: string | Symbol, listener?: ListenerFn, context?: any, once?: boolean): this,
+    emit(event: string, ...params?: any[]): this
+  }
+  declare module.exports: Class<EventEmitter>
+}
+
+// Filename aliases
+declare module 'eventemitter3/index' {
+  declare module.exports: $Exports<'eventemitter3'>
+}
+declare module 'eventemitter3/index.js' {
+  declare module.exports: $Exports<'eventemitter3'>
+}

packages/metro/src/lib/bundle-modules/WebSocketHMRClient.js

@@ -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.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 'use strict';