[Auth] Fix double-onAuthStateChanged call bug (#5686)

* Fix double-onAuthStateChanged call bug * Add changeset * PR feedback

Author: sam-gc

.changeset/thirty-rats-worry.md

@@ -0,0 +1,5 @@
+---
+"@firebase/auth": patch
+---
+
+Fix bug that caused onAuthStateChanged to be fired twice

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

@@ -139,6 +139,7 @@ export class AuthImpl implements AuthInternal, _FirebaseService {
  }
 
  await this.initializeCurrentUser(popupRedirectResolver);
+ this.lastNotifiedUid = this.currentUser?.uid || null;
 
  if (this._deleted) {
  return;

packages/auth/src/platform_browser/auth.test.ts

@@ -319,6 +319,25 @@ describe('core/auth/initializeAuth', () => {
  });
  });
 
+ it('initialization sets the callback UID correctly', async () => {
+ const stub = sinon.stub(
+ _getInstance<PersistenceInternal>(inMemoryPersistence)
+ );
+ stub._get.returns(Promise.resolve(testUser(oldAuth, 'uid').toJSON()));
+ let authStateChangeCalls = 0;
+
+ const auth = await initAndWait(inMemoryPersistence) as AuthInternal;
+ auth.onAuthStateChanged(() => {
+ authStateChangeCalls++;
+ });
+
+ await auth._updateCurrentUser(testUser(auth, 'uid'));
+ await new Promise(resolve => {
+ setTimeout(resolve, 200);
+ });
+ expect(authStateChangeCalls).to.eq(1);
+ });
+
  context('#tryRedirectSignIn', () => {
  it('returns null and clears the redirect user in case of error', async () => {
  const stub = sinon.stub(

packages/auth/test/integration/webdriver/persistence.test.ts

@@ -445,7 +445,7 @@ browserDescribe('WebDriver persistence test', (driver, browser) => {
  await driver.call(CoreFunction.SIGN_OUT);
  expect(await driver.getUserSnapshot()).to.be.null;
  await driver.selectMainWindow({ noWait: true });
- await driver.pause(500);
+ await driver.pause(700);
  expect(await driver.getUserSnapshot()).to.be.null;
 
  const cred2: UserCredential = await driver.call(