Refactor proxy support to match Firebase Admin SDK capabilities

Based on research and feedback from issue #220:
- Remove httpsAgent support (Firebase only supports httpAgent in AppOptions)
- Pass httpAgent to credential factory for proper authentication proxy support
- Single httpAgent parameter handles both HTTP and HTTPS connections
- Update documentation to clarify httpAgent usage with HttpsProxyAgent for HTTPS proxies
- Update tests to reflect httpAgent-only configuration
- Maintain legacyHttpTransport support for HTTP/1.1 transport

All 88 tests passing (87 existing + 1 legacyHttpTransport test)

Simplify credential assignment using || operator

Replace if/else block with more concise || operator for getting or creating
credential with httpAgent support. Maintains same functionality while improving
readability.

Author: alex-friedl

.github/copilot-instructions.md

@@ -68,9 +68,8 @@ This repository implements a Node.js module for sending push notifications acros
 - `storageBucket` (optional) - Cloud Storage bucket
 - `serviceAccountId` (optional) - Service account email
 - `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)
+- `httpAgent` (optional) - HTTP/HTTPS proxy agent for network requests (use HttpProxyAgent for HTTP proxies, HttpsProxyAgent for HTTPS proxies)
+- `legacyHttpTransport` (optional) - Enable HTTP/1.1 transport instead of HTTP/2 (for compatibility with older Node.js or network restrictions, required for proper proxy support)
 
 All optional properties are dynamically added to Firebase initialization if defined.
 

README.md

@@ -59,8 +59,7 @@ const settings = {
         databaseURL: 'https://your-database.firebaseio.com', // Realtime Database URL (optional)
         storageBucket: 'your-bucket.appspot.com', // Cloud Storage bucket (optional)
         serviceAccountId: '[email protected]', // Service account email (optional)
-        httpAgent: undefined, // HTTP Agent for proxy support (optional)
-        httpsAgent: undefined, // HTTPS Agent for proxy support (optional)
+        httpAgent: undefined, // HTTP Agent for proxy support - use HttpProxyAgent for HTTP proxies, HttpsProxyAgent for HTTPS proxies (optional)
         legacyHttpTransport: false, // Enable HTTP/1.1 instead of HTTP/2 (optional)
     },
     apn: {
@@ -475,8 +474,7 @@ The following Firebase Admin SDK `AppOptions` are supported and can be passed in
 - `storageBucket` - Cloud Storage bucket name (optional)
 - `serviceAccountId` - Service account email (optional)
 - `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)
+- `httpAgent` - HTTP/HTTPS Agent for proxy support (optional, use HttpProxyAgent for HTTP proxies, HttpsProxyAgent for HTTPS proxies, 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

src/sendFCM.js

@@ -67,15 +67,19 @@ const sendChunk = (firebaseApp, recipients, message) => {
 
 const sendFCM = (regIds, data, settings) => {
   const appName = `${settings.fcm.appName}`;
+
+  // Get or create credential with httpAgent for proper proxy support in authentication
+  const credential =
+    settings.fcm.credential ||
+    firebaseAdmin.credential.cert(settings.fcm.serviceAccountKey, settings.fcm.httpAgent);
+
   const opts = {
-    credential:
-      settings.fcm.credential || firebaseAdmin.credential.cert(settings.fcm.serviceAccountKey),
+    credential,
   };
 
   // Add optional Firebase AppOptions properties if provided
   const optionalProps = [
     'httpAgent',
-    'httpsAgent',
     'projectId',
     'databaseURL',
     'storageBucket',

test/send/sendFCM.js

@@ -154,47 +154,8 @@ describe('push-notifications-fcm', () => {
         });
     });
 
-    it('should accept httpsAgent in settings', (done) => {
-      const mockHttpsAgent = {};
-      const mockInitializeApp = sinon.stub(firebaseAdmin, 'initializeApp').returns({
-        messaging: () => ({
-          sendEachForMulticast: () =>
-            Promise.resolve({
-              successCount: 1,
-              failureCount: 0,
-              responses: [{ error: null }],
-            }),
-        }),
-      });
-
-      const fcmOptsWithProxy = {
-        fcm: {
-          name: 'testAppNameProxyHttps',
-          credential: { getAccessToken: () => Promise.resolve({}) },
-          httpsAgent: mockHttpsAgent,
-        },
-      };
-
-      const pnWithProxy = new PN(fcmOptsWithProxy);
-
-      pnWithProxy
-        .send(regIds, message)
-        .then(() => {
-          // Verify that initializeApp was called with httpsAgent
-          const callArgs = mockInitializeApp.getCall(0).args[0];
-          expect(callArgs.httpsAgent).to.equal(mockHttpsAgent);
-          mockInitializeApp.restore();
-          done();
-        })
-        .catch((err) => {
-          mockInitializeApp.restore();
-          done(err);
-        });
-    });
-
-    it('should accept both httpAgent and httpsAgent in settings', (done) => {
+    it('should accept httpAgent in settings for both HTTP and HTTPS', (done) => {
       const mockHttpAgent = {};
-      const mockHttpsAgent = {};
       const mockInitializeApp = sinon.stub(firebaseAdmin, 'initializeApp').returns({
         messaging: () => ({
           sendEachForMulticast: () =>
@@ -208,10 +169,9 @@ describe('push-notifications-fcm', () => {
 
       const fcmOptsWithProxy = {
         fcm: {
-          name: 'testAppNameProxyBoth',
+          name: 'testAppNameProxyHttpsViaHttpAgent',
           credential: { getAccessToken: () => Promise.resolve({}) },
           httpAgent: mockHttpAgent,
-          httpsAgent: mockHttpsAgent,
         },
       };
 
@@ -220,10 +180,10 @@ describe('push-notifications-fcm', () => {
       pnWithProxy
         .send(regIds, message)
         .then(() => {
-          // Verify that initializeApp was called with both agents
+          // Verify that initializeApp was called with httpAgent
+          // httpAgent handles both HTTP and HTTPS connections in Firebase Admin SDK
           const callArgs = mockInitializeApp.getCall(0).args[0];
           expect(callArgs.httpAgent).to.equal(mockHttpAgent);
-          expect(callArgs.httpsAgent).to.equal(mockHttpsAgent);
           mockInitializeApp.restore();
           done();
         })