Implement onFirebaseTokenChanged method (#9334)

* Implement onFirebaseTokenChanged method

Author: mansisampat

packages/auth/src/core/auth/auth_impl.test.ts

@@ -553,28 +553,62 @@ describe('core/auth/auth_impl', () => {
       expect(callbackCalled).to.be.false;
     });
 
+    it('immediately calls firebaseTokenChange if initialization finished', done => {
+      const token: FirebaseToken = {
+        token: 'test-token',
+        expirationTime: 123456
+      };
+      (auth as any).firebaseToken = token;
+      auth._isInitialized = true;
+      auth.onFirebaseTokenChanged(t => {
+        expect(t).to.eq(token);
+        done();
+      });
+    });
+
+    it('waits for initialization for onFirebaseTokenChanged', done => {
+      const token: FirebaseToken = {
+        token: 'test-token',
+        expirationTime: 123456
+      };
+      (auth as any).firebaseToken = token;
+      auth._isInitialized = false;
+      auth.onFirebaseTokenChanged(t => {
+        expect(t).to.eq(token);
+        done();
+      });
+    });
+
     describe('user logs in/out, tokens refresh', () => {
       let user: UserInternal;
       let authStateCallback: sinon.SinonSpy;
       let idTokenCallback: sinon.SinonSpy;
       let beforeAuthCallback: sinon.SinonSpy;
+      let firebaseTokenCallback: sinon.SinonSpy;
+      const testFirebaseToken: FirebaseToken = {
+        token: 'test-fb-token',
+        expirationTime: 123456789
+      };
 
       beforeEach(() => {
         user = testUser(auth, 'uid');
         authStateCallback = sinon.spy();
         idTokenCallback = sinon.spy();
         beforeAuthCallback = sinon.spy();
+        firebaseTokenCallback = sinon.spy();
       });
 
       context('initially currentUser is null', () => {
         beforeEach(async () => {
           auth.onAuthStateChanged(authStateCallback);
           auth.onIdTokenChanged(idTokenCallback);
           auth.beforeAuthStateChanged(beforeAuthCallback);
+          auth.onFirebaseTokenChanged(firebaseTokenCallback);
           await auth._updateCurrentUser(null);
           authStateCallback.resetHistory();
           idTokenCallback.resetHistory();
           beforeAuthCallback.resetHistory();
+          firebaseTokenCallback.resetHistory();
         });
 
         it('onAuthStateChange triggers on log in', async () => {
@@ -591,17 +625,26 @@ describe('core/auth/auth_impl', () => {
           await auth._updateCurrentUser(user);
           expect(beforeAuthCallback).to.have.been.calledWith(user);
         });
+
+        it('onFirebaseTokenChanged triggers on token set', async () => {
+          await auth._updateFirebaseToken(testFirebaseToken);
+          expect(firebaseTokenCallback).to.have.been.calledWith(
+            testFirebaseToken
+          );
+        });
       });
 
       context('initially currentUser is user', () => {
         beforeEach(async () => {
           auth.onAuthStateChanged(authStateCallback);
           auth.onIdTokenChanged(idTokenCallback);
           auth.beforeAuthStateChanged(beforeAuthCallback);
+          auth.onFirebaseTokenChanged(firebaseTokenCallback);
           await auth._updateCurrentUser(user);
           authStateCallback.resetHistory();
           idTokenCallback.resetHistory();
           beforeAuthCallback.resetHistory();
+          firebaseTokenCallback.resetHistory();
         });
 
         it('onAuthStateChange triggers on log out', async () => {
@@ -638,6 +681,43 @@ describe('core/auth/auth_impl', () => {
         });
       });
 
+      context('initially firebaseToken is null', () => {
+        beforeEach(async () => {
+          auth.onFirebaseTokenChanged(firebaseTokenCallback);
+          await auth._updateFirebaseToken(null);
+          firebaseTokenCallback.resetHistory();
+        });
+
+        it('onFirebaseTokenChanged triggers on token set', async () => {
+          await auth._updateFirebaseToken(testFirebaseToken);
+          expect(firebaseTokenCallback).to.have.been.calledWith(
+            testFirebaseToken
+          );
+        });
+      });
+
+      context('initially firebaseToken is token', () => {
+        beforeEach(async () => {
+          auth.onFirebaseTokenChanged(firebaseTokenCallback);
+          await auth._updateFirebaseToken(testFirebaseToken);
+          firebaseTokenCallback.resetHistory();
+        });
+
+        it('onFirebaseTokenChanged triggers on token set to null', async () => {
+          await auth._updateFirebaseToken(null);
+          expect(firebaseTokenCallback).to.have.been.calledWith(null);
+        });
+
+        it('onFirebaseTokenChanged triggers for token props change', async () => {
+          const newToken: FirebaseToken = {
+            ...testFirebaseToken,
+            token: 'new-fb-token'
+          };
+          await auth._updateFirebaseToken(newToken);
+          expect(firebaseTokenCallback).to.have.been.calledWith(newToken);
+        });
+      });
+
       context('with Proactive Refresh', () => {
         let oldUser: UserInternal;
 
@@ -739,6 +819,20 @@ describe('core/auth/auth_impl', () => {
         expect(cb2).to.have.been.calledWith(user);
       });
 
+      it('onFirebaseTokenChanged works for multiple listeners', async () => {
+        const cb1 = sinon.spy();
+        const cb2 = sinon.spy();
+        auth.onFirebaseTokenChanged(cb1);
+        auth.onFirebaseTokenChanged(cb2);
+        await auth._updateFirebaseToken(null);
+        cb1.resetHistory();
+        cb2.resetHistory();
+
+        await auth._updateFirebaseToken(testFirebaseToken);
+        expect(cb1).to.have.been.calledWith(testFirebaseToken);
+        expect(cb2).to.have.been.calledWith(testFirebaseToken);
+      });
+
       it('_updateCurrentUser throws if a beforeAuthStateChange callback throws', async () => {
         await auth._updateCurrentUser(null);
         const cb1 = sinon.stub().throws();

packages/auth/src/core/auth/auth_impl.ts

@@ -672,6 +672,19 @@ export class AuthImpl implements AuthInternal, _FirebaseService {
     );
   }
 
+  onFirebaseTokenChanged(
+    nextOrObserver: NextOrObserver<FirebaseToken>,
+    error?: ErrorFn,
+    completed?: CompleteFn
+  ): Unsubscribe | undefined {
+    return this.registerStateListener(
+      this.firebaseTokenSubscription,
+      nextOrObserver,
+      error,
+      completed
+    );
+  }
+
   authStateReady(): Promise<void> {
     return new Promise((resolve, reject) => {
       if (this.currentUser) {

packages/auth/src/model/auth.ts

@@ -18,12 +18,16 @@
 import {
   Auth,
   AuthSettings,
+  CompleteFn,
   Config,
   EmulatorConfig,
+  ErrorFn,
+  NextOrObserver,
   PasswordPolicy,
   PasswordValidationStatus,
   PopupRedirectResolver,
   TenantConfig,
+  Unsubscribe,
   User
 } from './public_types';
 import { ErrorFactory } from '@firebase/util';
@@ -77,6 +81,11 @@ export interface AuthInternal extends Auth {
   currentUser: User | null;
   emulatorConfig: EmulatorConfig | null;
   getFirebaseAccessToken(forceRefresh?: boolean): Promise<string | null>;
+  onFirebaseTokenChanged(
+    nextOrObserver: NextOrObserver<FirebaseToken>,
+    error?: ErrorFn,
+    completed?: CompleteFn
+  ): Unsubscribe | undefined;
   _agentRecaptchaConfig: RecaptchaConfig | null;
   _tenantRecaptchaConfigs: Record<string, RecaptchaConfig>;
   _projectPasswordPolicy: PasswordPolicy | null;