Add support for legacyHttpTransport flag

Author: alex-friedl

.github/copilot-instructions.md

@@ -67,6 +67,7 @@ This repository implements a Node.js module for sending push notifications acros
 - `databaseAuthVariableOverride` (optional) - Auth override for RTDB rules
 - `httpAgent` (optional) - HTTP proxy agent for network requests
 - `httpsAgent` (optional) - HTTPS proxy agent for network requests
+- `legacyHttpTransport` (optional) - Enable HTTP/1.1 transport instead of HTTP/2 (for compatibility with older Node.js or network restrictions)
 
 All optional properties are dynamically added to Firebase initialization if defined.
 

README.md

@@ -61,6 +61,7 @@ const settings = {
         serviceAccountId: 'your-email@your-project.iam.gserviceaccount.com', // Service account email (optional)
         httpAgent: undefined, // HTTP Agent for proxy support (optional)
         httpsAgent: undefined, // HTTPS Agent for proxy support (optional)
+        legacyHttpTransport: false, // Enable HTTP/1.1 instead of HTTP/2 (optional)
     },
     apn: {
         token: {
@@ -476,6 +477,7 @@ The following Firebase Admin SDK `AppOptions` are supported and can be passed in
 - `databaseAuthVariableOverride` - Auth variable override for Realtime Database (optional)
 - `httpAgent` - HTTP Agent for proxy support (optional, see [Proxy](#proxy) section)
 - `httpsAgent` - HTTPS Agent for proxy support (optional, see [Proxy](#proxy) section)
+- `legacyHttpTransport` - Enable HTTP/1.1 transport instead of HTTP/2 (optional, for compatibility with older Node.js versions or network restrictions)
 
 ```js
 const tokens = ['e..Gwso:APA91.......7r910HljzGUVS_f...kbyIFk2sK6......D2s6XZWn2E21x'];

src/sendFCM.js

@@ -89,6 +89,12 @@ const sendFCM = (regIds, data, settings) => {
   });
 
   const firebaseApp = firebaseAdmin.initializeApp(opts, appName);
+
+  // Enable legacy HTTP/1.1 transport if requested
+  if (settings.fcm.legacyHttpTransport) {
+    firebaseAdmin.messaging(firebaseApp).enableLegacyHttpTransport();
+  }
+
   firebaseAdmin.INTERNAL.appStore.removeApp(appName);
 
   const promises = [];

test/send/sendFCM.js

@@ -469,4 +469,141 @@ describe('push-notifications-fcm', () => {
         });
     });
   });
+
+  describe('Legacy HTTP transport support', () => {
+    it('should enable legacyHttpTransport when configured', (done) => {
+      const mockEnableLegacyHttpTransport = sinon.stub();
+
+      // Create mock messaging instance
+      const mockMessagingInstance = {
+        enableLegacyHttpTransport: mockEnableLegacyHttpTransport,
+        sendEachForMulticast: () =>
+          Promise.resolve({
+            successCount: 1,
+            failureCount: 0,
+            responses: [{ error: null }],
+          }),
+      };
+
+      // Stub initializeApp and INTERNAL.appStore.removeApp
+      const initStub = sinon.stub(firebaseAdmin, 'initializeApp').returns({});
+      const removeStub = sinon.stub(firebaseAdmin.INTERNAL.appStore, 'removeApp');
+
+      // Use sinon.stub with an object and property descriptor
+      const getMessagingStub = sinon.stub();
+      getMessagingStub.returns(mockMessagingInstance);
+
+      // Replace the getter for messaging
+      const descriptor = Object.getOwnPropertyDescriptor(
+        Object.getPrototypeOf(firebaseAdmin),
+        'messaging'
+      );
+      const originalMessaging = descriptor.get;
+      Object.defineProperty(firebaseAdmin, 'messaging', {
+        value: getMessagingStub,
+        configurable: true,
+      });
+
+      const fcmOptsWithLegacy = {
+        fcm: {
+          name: 'testAppNameLegacy',
+          credential: { getAccessToken: () => Promise.resolve({}) },
+          legacyHttpTransport: true,
+        },
+      };
+
+      const pnWithLegacy = new PN(fcmOptsWithLegacy);
+
+      pnWithLegacy
+        .send(regIds, message)
+        .then(() => {
+          expect(mockEnableLegacyHttpTransport.called).to.be.true;
+          // Restore
+          initStub.restore();
+          removeStub.restore();
+          Object.defineProperty(firebaseAdmin, 'messaging', {
+            get: originalMessaging,
+            configurable: true,
+          });
+          done();
+        })
+        .catch((err) => {
+          // Restore
+          initStub.restore();
+          removeStub.restore();
+          Object.defineProperty(firebaseAdmin, 'messaging', {
+            get: originalMessaging,
+            configurable: true,
+          });
+          done(err);
+        });
+    });
+
+    it('should not enable legacyHttpTransport when not configured', (done) => {
+      const mockEnableLegacyHttpTransport = sinon.stub();
+
+      // Create mock messaging instance
+      const mockMessagingInstance = {
+        enableLegacyHttpTransport: mockEnableLegacyHttpTransport,
+        sendEachForMulticast: () =>
+          Promise.resolve({
+            successCount: 1,
+            failureCount: 0,
+            responses: [{ error: null }],
+          }),
+      };
+
+      // Stub initializeApp and INTERNAL.appStore.removeApp
+      const initStub = sinon.stub(firebaseAdmin, 'initializeApp').returns({});
+      const removeStub = sinon.stub(firebaseAdmin.INTERNAL.appStore, 'removeApp');
+
+      // Use sinon.stub with an object and property descriptor
+      const getMessagingStub = sinon.stub();
+      getMessagingStub.returns(mockMessagingInstance);
+
+      // Replace the getter for messaging
+      const descriptor = Object.getOwnPropertyDescriptor(
+        Object.getPrototypeOf(firebaseAdmin),
+        'messaging'
+      );
+      const originalMessaging = descriptor.get;
+      Object.defineProperty(firebaseAdmin, 'messaging', {
+        value: getMessagingStub,
+        configurable: true,
+      });
+
+      const fcmOptsWithoutLegacy = {
+        fcm: {
+          name: 'testAppNameNoLegacy',
+          credential: { getAccessToken: () => Promise.resolve({}) },
+        },
+      };
+
+      const pnWithoutLegacy = new PN(fcmOptsWithoutLegacy);
+
+      pnWithoutLegacy
+        .send(regIds, message)
+        .then(() => {
+          expect(mockEnableLegacyHttpTransport.called).to.be.false;
+          // Restore
+          initStub.restore();
+          removeStub.restore();
+          Object.defineProperty(firebaseAdmin, 'messaging', {
+            get: originalMessaging,
+            configurable: true,
+          });
+          done();
+        })
+        .catch((err) => {
+          // Restore
+          initStub.restore();
+          removeStub.restore();
+          Object.defineProperty(firebaseAdmin, 'messaging', {
+            get: originalMessaging,
+            configurable: true,
+          });
+          done(err);
+        });
+    });
+  });
 });