feat: Add Firebase Cloud Messaging (FCM) HTTP/2 support and option `f…

…cmEnableLegacyHttpTransport` to use legacy HTTP/1.1 (#274)

README.md

@@ -19,8 +19,10 @@ The official Push Notification adapter for Parse Server. See [Parse Server Push
 - [Configure Parse Server](#configure-parse-server)
   - [Apple Push Options](#apple-push-options)
   - [Android Push Options](#android-push-options)
+  - [Firebase Cloud Messaging (FCM)](#firebase-cloud-messaging-fcm)
     - [Google Cloud Service Account Key](#google-cloud-service-account-key)
     - [Migration to FCM HTTP v1 API (June 2024)](#migration-to-fcm-http-v1-api-june-2024)
+    - [HTTP/1.1 Legacy Option](#http11-legacy-option)
   - [Expo Push Options](#expo-push-options)
 - [Bundled with Parse Server](#bundled-with-parse-server)
 - [Logging](#logging)
@@ -110,6 +112,10 @@ android: {
 }
 ```
 
+### Firebase Cloud Messaging (FCM)
+
+This section contains some considerations when using FCM, regardless of the destination ecosystems the push notification is sent to.
+
 #### Google Cloud Service Account Key
 
 The Firebase console allows to easily create and download a Google Cloud service account key JSON file with the required permissions. Instead of setting `firebaseServiceAccount` to the path of the JSON file, you can provide an object representing a Google Cloud service account key:
@@ -139,6 +145,19 @@ android: {
 }
 ```
 
+#### HTTP/1.1 Legacy Option
+
+With the introduction of the FCM HTTP v1 API, support for HTTP/2 was added which provides faster throughput for push notifications. To use the older version HTTP/1.1 set `fcmEnableLegacyHttpTransport: true` in your push options.
+
+Example options:
+
+```js
+android: {
+  firebaseServiceAccount: __dirname + '/firebase.json',
+  fcmEnableLegacyHttpTransport: true
+}
+```
+
 ### Expo Push Options
 
 Example options:

package.json

@@ -27,7 +27,7 @@
     "@parse/node-apn": "6.0.1",
     "@parse/node-gcm": "1.0.2",
     "expo-server-sdk": "3.10.0",
-    "firebase-admin": "12.2.0",
+    "firebase-admin": "12.3.0",
     "npmlog": "7.0.1",
     "parse": "5.2.0",
     "web-push": "3.6.7"

spec/FCM.spec.js

@@ -1,6 +1,7 @@
 import path from 'path';
 import log from 'npmlog';
 import FCM from '../src/FCM.js';
+import { getApps, deleteApp } from 'firebase-admin/app';
 
 const testArgs = {
   firebaseServiceAccount: path.join(
@@ -13,6 +14,10 @@ const testArgs = {
 };
 
 describe('FCM', () => {
+  beforeEach(async () => {
+    getApps().forEach(app => deleteApp(app));
+  });
+
   it('can initialize', () => {
     const fcm = new FCM(testArgs);
     expect(fcm).toBeDefined();
@@ -31,6 +36,37 @@ describe('FCM', () => {
     expect(spy).toHaveBeenCalledWith('parse-server-push-adapter FCM', 'invalid push payload');
   });
 
+  it('initializes with fcmEnableLegacyHttpTransport set to false by default', () => {
+    const fcm = new FCM(testArgs);
+    expect(fcm).toBeDefined();
+    expect(fcm.sender).toBeDefined();
+    expect(fcm.sender.useLegacyTransport).toEqual(false);
+  });
+
+  it('can initialize with fcmEnableLegacyHttpTransport set to false', () => {
+    const legacyHttpTransportArgs = {
+      ...testArgs,
+      fcmEnableLegacyHttpTransport: false
+    };
+
+    const fcm = new FCM(legacyHttpTransportArgs);
+    expect(fcm).toBeDefined();
+    expect(fcm.sender).toBeDefined();
+    expect(fcm.sender.useLegacyTransport).toEqual(false);
+  });
+
+  it('can initialize with fcmEnableLegacyHttpTransport set to true', () => {
+    const legacyHttpTransportArgs = {
+      ...testArgs,
+      fcmEnableLegacyHttpTransport: true
+    };
+
+    const fcm = new FCM(legacyHttpTransportArgs);
+    expect(fcm).toBeDefined();
+    expect(fcm.sender).toBeDefined();
+    expect(fcm.sender.useLegacyTransport).toEqual(true);
+  });
+
   it('can send successful FCM android request', async () => {
     const spyVerbose = spyOn(log, 'verbose').and.callFake(() => {});
     const spyInfo = spyOn(log, 'info').and.callFake(() => {});

src/FCM.js

@@ -25,14 +25,26 @@ export default function FCM(args, pushType) {
     );
   }
 
+  const fcmEnableLegacyHttpTransport = typeof args.fcmEnableLegacyHttpTransport === 'boolean'
+    ? args.fcmEnableLegacyHttpTransport
+    : false;
+
   let app;
   if (getApps().length === 0) {
     app = initializeApp({ credential: cert(args.firebaseServiceAccount) });
   } else {
     app = getApp();
   }
+
   this.sender = getMessaging(app);
-  this.pushType = pushType; // Push type is only used to remain backwards compatible with APNS and GCM
+
+  if (fcmEnableLegacyHttpTransport) {
+    this.sender.enableLegacyHttpTransport();
+    log.warn(LOG_PREFIX, 'Legacy HTTP/1.1 transport is enabled. This is a deprecated feature and support for this flag will be removed in the future.');
+  }
+
+  // Push type is only used to remain backwards compatible with APNS and GCM
+  this.pushType = pushType;
 }
 
 FCM.FCMRegistrationTokensMax = FCMRegistrationTokensMax;