Address version conflict when used together with firebase-admin (#1916)

* abstract SDK_VERSION

* some comment

* remove the unnecessary build target

* require default

* [AUTOMATED]: Prettier Code Styling

* [AUTOMATED]: License Headers

* remove experimental changes

* remove unused var

* only ignore MODULE_NOT_FOUND error

* [AUTOMATED]: Prettier Code Styling

* revert module export change

Author: Feiyang1

packages/database/index.node.ts

@@ -15,9 +15,7 @@
  * limitations under the License.
  */
 
-import firebase from '@firebase/app';
-import { CONSTANTS, isNodeSdk } from '@firebase/util';
-import { FirebaseApp, FirebaseNamespace } from '@firebase/app-types';
+import { FirebaseNamespace, FirebaseApp } from '@firebase/app-types';
 import { _FirebaseNamespace } from '@firebase/app-types/private';
 import { Database } from './src/api/Database';
 import { DataSnapshot } from './src/api/DataSnapshot';
@@ -29,30 +27,26 @@ import * as INTERNAL from './src/api/internal';
 import * as TEST_ACCESS from './src/api/test_access';
 import './src/nodePatches';
 import * as types from '@firebase/database-types';
+import { setSDKVersion } from './src/core/version';
+import { CONSTANTS, isNodeSdk } from '@firebase/util';
+
+const ServerValue = Database.ServerValue;
 
 /**
  * A one off register function which returns a database based on the app and
  * passed database URL.
  *
  * @param app A valid FirebaseApp-like object
  * @param url A valid Firebase databaseURL
+ * @param version custom version e.g. firebase-admin version
  */
-
-const ServerValue = Database.ServerValue;
-
-export function initStandalone(
-  app: FirebaseApp,
-  url: string,
-  version?: string
-) {
+export function initStandalone(app: FirebaseApp, url: string, version: string) {
   /**
    * This should allow the firebase-admin package to provide a custom version
    * to the backend
    */
   CONSTANTS.NODE_ADMIN = true;
-  if (version) {
-    firebase.SDK_VERSION = version;
-  }
+  setSDKVersion(version);
 
   return {
     instance: RepoManager.getInstance().databaseFromApp(app, url),
@@ -70,6 +64,9 @@ export function initStandalone(
 }
 
 export function registerDatabase(instance: FirebaseNamespace) {
+  // set SDK_VERSION
+  setSDKVersion(instance.SDK_VERSION);
+
   // Register the Database Service with the 'firebase' namespace.
   const namespace = (instance as _FirebaseNamespace).INTERNAL.registerService(
     'database',
@@ -94,7 +91,21 @@ export function registerDatabase(instance: FirebaseNamespace) {
   }
 }
 
-registerDatabase(firebase);
+try {
+  // If @firebase/app is not present, skip registering database.
+  // It could happen when this package is used in firebase-admin which doesn't depend on @firebase/app.
+  // Previously firebase-admin depends on @firebase/app, which causes version conflict on
+  // @firebase/app when used together with the js sdk. More detail:
+  // https://github.com/firebase/firebase-js-sdk/issues/1696#issuecomment-501546596
+  const firebase = require('@firebase/app').default;
+  registerDatabase(firebase);
+} catch (err) {
+  // catch and ignore 'MODULE_NOT_FOUND' error in firebase-admin context
+  // we can safely ignore this error because RTDB in firebase-admin works without @firebase/app
+  if (err.code !== 'MODULE_NOT_FOUND') {
+    throw err;
+  }
+}
 
 // Types to export for the admin SDK
 export { Database, Query, Reference, enableLogging, ServerValue };

packages/database/index.ts

@@ -16,7 +16,7 @@
  */
 
 import firebase from '@firebase/app';
-import { FirebaseApp, FirebaseNamespace } from '@firebase/app-types';
+import { FirebaseNamespace } from '@firebase/app-types';
 import { _FirebaseNamespace } from '@firebase/app-types/private';
 import { Database } from './src/api/Database';
 import { DataSnapshot } from './src/api/DataSnapshot';
@@ -28,10 +28,14 @@ import * as INTERNAL from './src/api/internal';
 import * as TEST_ACCESS from './src/api/test_access';
 import { isNodeSdk } from '@firebase/util';
 import * as types from '@firebase/database-types';
+import { setSDKVersion } from './src/core/version';
 
 const ServerValue = Database.ServerValue;
 
 export function registerDatabase(instance: FirebaseNamespace) {
+  // set SDK_VERSION
+  setSDKVersion(instance.SDK_VERSION);
+
   // Register the Database Service with the 'firebase' namespace.
   const namespace = (instance as _FirebaseNamespace).INTERNAL.registerService(
     'database',

packages/database/src/core/PersistentConnection.ts

@@ -15,8 +15,7 @@
  * limitations under the License.
  */
 
-import firebase from '@firebase/app';
-import { contains, isEmpty, safeGet } from '@firebase/util';
+import { contains, isEmpty, safeGet, CONSTANTS } from '@firebase/util';
 import { stringify } from '@firebase/util';
 import { assert } from '@firebase/util';
 import { error, log, logWrapper, warn, ObjectToUniqueKey } from './util/util';
@@ -25,12 +24,12 @@ import { VisibilityMonitor } from './util/VisibilityMonitor';
 import { OnlineMonitor } from './util/OnlineMonitor';
 import { isAdmin, isValidFormat } from '@firebase/util';
 import { Connection } from '../realtime/Connection';
-import { CONSTANTS } from '@firebase/util';
 import { isMobileCordova, isReactNative, isNodeSdk } from '@firebase/util';
 import { ServerActions } from './ServerActions';
 import { AuthTokenProvider } from './AuthTokenProvider';
 import { RepoInfo } from './RepoInfo';
 import { Query } from '../api/Query';
+import { SDK_VERSION } from './version';
 
 const RECONNECT_MIN_DELAY = 1000;
 const RECONNECT_MAX_DELAY_DEFAULT = 60 * 5 * 1000; // 5 minutes in milliseconds (Case: 1858)
@@ -926,9 +925,7 @@ export class PersistentConnection extends ServerActions {
       clientName = 'node';
     }
 
-    stats[
-      'sdk.' + clientName + '.' + firebase.SDK_VERSION.replace(/\./g, '-')
-    ] = 1;
+    stats['sdk.' + clientName + '.' + SDK_VERSION.replace(/\./g, '-')] = 1;
 
     if (isMobileCordova()) {
       stats['framework.cordova'] = 1;

packages/database/src/core/version.ts

@@ -0,0 +1,24 @@
+/**
+ * @license
+ * Copyright 2019 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/** The semver (www.semver.org) version of the SDK. */
+export let SDK_VERSION = '';
+
+// SDK_VERSION should be set before any database instance is created
+export function setSDKVersion(version: string): void {
+  SDK_VERSION = version;
+}

packages/database/src/realtime/WebSocketConnection.ts

@@ -19,8 +19,7 @@ import { RepoInfo } from '../core/RepoInfo';
 
 declare const MozWebSocket: any;
 
-import firebase from '@firebase/app';
-import { assert } from '@firebase/util';
+import { assert, CONSTANTS as ENV_CONSTANTS } from '@firebase/util';
 import { logWrapper, splitStringBySize } from '../core/util/util';
 import { StatsManager } from '../core/stats/StatsManager';
 import {
@@ -33,12 +32,12 @@ import {
   VERSION_PARAM,
   WEBSOCKET
 } from './Constants';
-import { CONSTANTS as ENV_CONSTANTS } from '@firebase/util';
 import { PersistentStorage } from '../core/storage/storage';
 import { jsonEval, stringify } from '@firebase/util';
 import { isNodeSdk } from '@firebase/util';
 import { Transport } from './Transport';
 import { StatsCollection } from '../core/stats/StatsCollection';
+import { SDK_VERSION } from '../core/version';
 
 const WEBSOCKET_MAX_FRAME_SIZE = 16384;
 const WEBSOCKET_KEEPALIVE_INTERVAL = 45000;
@@ -150,9 +149,9 @@ export class WebSocketConnection implements Transport {
         // UA Format: Firebase/<wire_protocol>/<sdk_version>/<platform>/<device>
         const options: { [k: string]: object } = {
           headers: {
-            'User-Agent': `Firebase/${PROTOCOL_VERSION}/${
-              firebase.SDK_VERSION
-            }/${process.platform}/${device}`
+            'User-Agent': `Firebase/${PROTOCOL_VERSION}/${SDK_VERSION}/${
+              process.platform
+            }/${device}`
           }
         };