[flow] fixed flow errors in ModuleBase

lib/utils/ModuleBase.js

@@ -2,10 +2,12 @@
  * @flow
  */
 import { NativeModules } from 'react-native';
+
 import Log from '../utils/log';
-import { nativeWithApp } from './../utils';
 import INTERNALS from './../internals';
 import FirebaseCore from './../firebase';
+import FirebaseApp from '../firebase-app';
+import { nativeWithApp } from './../utils';
 
 const logs = {};
 
@@ -37,14 +39,23 @@ const DEFAULTS = {
 };
 
 export default class ModuleBase {
+  _native: Object;
+  _module: string;
+  _options: Object;
+  _appName: string;
+  _namespace: string;
+  _firebaseApp: Object;
+  _eventEmitter: Object;
+  static _NAMESPACE: string;
+  static _NATIVE_MODULE: string;
+
   /**
    *
    * @param firebaseApp
    * @param options
-   * @param moduleName
    * @param withEventEmitter
    */
-  constructor(firebaseApp, options, withEventEmitter = false) {
+  constructor(firebaseApp: Object, options: Object, withEventEmitter: boolean = false) {
     this._module = this.constructor._NATIVE_MODULE.replace('RNFirebase', '');
     this._firebaseApp = firebaseApp;
     this._appName = firebaseApp._name;
@@ -108,7 +119,7 @@ export default class ModuleBase {
    * Returns the FirebaseApp instance for current module
    * @return {*}
    */
-  get app() {
+  get app(): FirebaseApp {
     return this._firebaseApp;
   }
 
@@ -123,27 +134,27 @@ export default class ModuleBase {
    * Proxy functions to shared event emitter instance
    * https://github.com/facebook/react-native/blob/master/Libraries/EventEmitter/EventEmitter.js
    */
-  get sharedEventEmitter() {
+  get sharedEventEmitter(): Object {
     return INTERNALS.SharedEventEmitter;
   }
 
-  get addListener() {
+  get addListener(): Function {
     return INTERNALS.SharedEventEmitter.addListener.bind(INTERNALS.SharedEventEmitter);
   }
 
-  get once() {
+  get once(): Function {
     return INTERNALS.SharedEventEmitter.once.bind(INTERNALS.SharedEventEmitter);
   }
 
-  get on() {
+  get on(): Function {
     return INTERNALS.SharedEventEmitter.addListener.bind(INTERNALS.SharedEventEmitter);
   }
 
-  get emit() {
+  get emit(): Function {
     return INTERNALS.SharedEventEmitter.emit.bind(INTERNALS.SharedEventEmitter);
   }
 
-  get listeners() {
+  get listeners(): Function {
     return INTERNALS.SharedEventEmitter.listeners.bind(INTERNALS.SharedEventEmitter);
   }
 
@@ -152,11 +163,11 @@ export default class ModuleBase {
     return subscriptions && subscriptions.length;
   }
 
-  get removeListener() {
+  get removeListener(): Function {
     return INTERNALS.SharedEventEmitter.removeListener.bind(INTERNALS.SharedEventEmitter);
   }
 
-  get removeAllListeners() {
+  get removeAllListeners(): Function {
     return INTERNALS.SharedEventEmitter.removeAllListeners.bind(INTERNALS.SharedEventEmitter);
   }
 }