[fix] NativeEventEmitter implementation

Close #1275

Author: EvanBacon

packages/react-native-web/src/vendor/react-native/NativeEventEmitter/RCTDeviceEventEmitter.js

@@ -0,0 +1,72 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ * @flow
+ */
+
+'use strict';
+
+import EventEmitter from '../emitter/EventEmitter';
+import EventSubscriptionVendor from '../emitter/EventSubscriptionVendor';
+
+import type EmitterSubscription from '../emitter/EmitterSubscription';
+
+const __DEV__ = process.env.NODE_ENV !== 'production';
+
+function checkNativeEventModule(eventType: ?string) {
+  if (eventType) {
+    if (eventType === 'appStateDidChange' || eventType === 'memoryWarning') {
+      throw new Error(
+        '`' +
+          eventType +
+          '` event should be registered via the AppState module',
+      );
+    }
+  }
+}
+
+/**
+ * Deprecated - subclass NativeEventEmitter to create granular event modules instead of
+ * adding all event listeners directly to RCTDeviceEventEmitter.
+ */
+class RCTDeviceEventEmitter extends EventEmitter {
+  sharedSubscriber: EventSubscriptionVendor;
+
+  constructor() {
+    const sharedSubscriber = new EventSubscriptionVendor();
+    super(sharedSubscriber);
+    this.sharedSubscriber = sharedSubscriber;
+  }
+
+  addListener(
+    eventType: string,
+    listener: Function,
+    context: ?Object,
+  ): EmitterSubscription {
+    if (__DEV__) {
+      checkNativeEventModule(eventType);
+    }
+    return super.addListener(eventType, listener, context);
+  }
+
+  removeAllListeners(eventType: ?string) {
+    if (__DEV__) {
+      checkNativeEventModule(eventType);
+    }
+    super.removeAllListeners(eventType);
+  }
+
+  removeSubscription(subscription: EmitterSubscription) {
+    if (subscription.emitter !== this) {
+      subscription.emitter.removeSubscription(subscription);
+    } else {
+      super.removeSubscription(subscription);
+    }
+  }
+}
+
+export default new RCTDeviceEventEmitter();

packages/react-native-web/src/vendor/react-native/NativeEventEmitter/index.js

@@ -8,11 +8,11 @@
  * @flow
  */
 'use strict';
+import invariant from 'fbjs/lib/invariant';
 
 import EventEmitter from '../emitter/EventEmitter';
-import Platform from '../../../exports/Platform';
+import RCTDeviceEventEmitter from './RCTDeviceEventEmitter';
 
-import invariant from 'fbjs/lib/invariant';
 
 import type EmitterSubscription from '../emitter/EmitterSubscription';
 
@@ -29,11 +29,7 @@ class NativeEventEmitter extends EventEmitter {
   _nativeModule: ?NativeModule;
 
   constructor(nativeModule: ?NativeModule) {
-    super();
-    if (Platform.OS === 'ios') {
-      invariant(nativeModule, 'Native module cannot be null.');
-      this._nativeModule = nativeModule;
-    }
+    super(RCTDeviceEventEmitter.sharedSubscriber);
   }
 
   addListener(