Flutter Firebase Auth with Apple doesn't logout

Question

I've integrated an Apple sign in for Flutter.
Everything is working fine until the point when I have to logout from the Stores() page.

The app landing page (Home) shows a series of buttons to login with different apps:

• Google
• Anonymous
• Apple
• Email & Password

All of them are able to logout by using a logout button, but not Apple. Here is my code
main.dart

class Main extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return StreamProvider<User>.value(
        value: AuthService().user,
        child: MaterialApp(
          home: Wrapper(),
          routes: {
            "/stores": (_) => Stores()
          },
        ));
  }
}

Wrapper.dart

class Wrapper extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final user = Provider.of<User>(context);

    if (user == null) {
      return Home(); <-- Landing page before login
    } else {
      return Stores(); <-- Landing page after login, where the logout button is
    }
  }
}

Home.dart

class _HomeState extends State<Home> {
  final AuthService _auth = AuthService();
  bool loading = false;

  final welcomeText = 'Welcome';
  final subtitle = 'Make grocery chores easier';
  final anonymousButtonText = 'Skip';

  @override
  Widget build(BuildContext context) {
    return Stack(children: [
            AuthLayout(),
            Scaffold(
                backgroundColor: Colors.transparent,
                appBar: AppBar(
                  title: Center(child: Text(welcomeText)),
                  backgroundColor: Colors.transparent,
                ),
                body: SingleChildScrollView(
                    child: ConstrainedBox(
                        constraints: BoxConstraints(),
                        child: Center(
                            child: Column(
                                mainAxisAlignment: MainAxisAlignment.start,
                                children: <Widget> [

                              // Sign In with Apple
                              Padding(
                                  padding: EdgeInsets.all(8.0),
                                  child: FutureBuilder<Object>(
                                      future: _auth.appleSignInAvailable,
                                      builder: (context, snapshot) {
                                        if (snapshot.data == true) {
                                          return AppleSignInButton(
                                            onPressed: () async {
                                              FirebaseUser user =
                                                  await _auth.appleSignIn();
                                              if (user != null) {
                                                Navigator.pushReplacementNamed(context, "/stores");
                                              }
                                            },
                                          );
                                        } else {
                                          return Container();
                                        }
                                      })) ....
                             

AuthService.dart

class AuthService {
  final FirebaseAuth _auth = FirebaseAuth.instance;
  final GoogleSignIn _googleSignIn = new GoogleSignIn();

  // Create user object based on FirebaseUser
  User _userFromFirebaseUser(FirebaseUser user) {
    return user != null ? User(uid: user.uid) : null;
  }

  // Auth change user stream
  Stream<User> get user {
    return _auth.onAuthStateChanged.map(
        _userFromFirebaseUser);
  }

  // SignIn with Google
  Future signInGoogle() async {
    GoogleSignInAccount googleSignInAccount = await _googleSignIn.signIn();

    GoogleSignInAuthentication googleSignInAuthentication =
        await googleSignInAccount.authentication;

    AuthCredential credential = GoogleAuthProvider.getCredential(
        idToken: googleSignInAuthentication.idToken,
        accessToken: googleSignInAuthentication.accessToken);

    try {
      AuthResult result = (await _auth.signInWithCredential(credential));
      FirebaseUser user = result.user;
      return _userFromFirebaseUser(user);
    } catch (e) {
      print(e.toString());
      return null;
    }
  }

  // SignIn with Apple
  // Determine if Apple Signin is available on device
  Future<bool> get appleSignInAvailable => AppleSignIn.isAvailable();
  Future appleSignIn() async {
    try {
      final AuthorizationResult appleResult =
          await AppleSignIn.performRequests([
        AppleIdRequest(requestedScopes: [Scope.email, Scope.fullName])
      ]);

      if (appleResult.error != null) {
        // handle error from Apple
      }

      final AuthCredential credential = OAuthProvider(providerId: 'apple.com')
          .getCredential(
              accessToken: String.fromCharCodes(
                  appleResult.credential.authorizationCode),
              idToken:
                  String.fromCharCodes(appleResult.credential.identityToken));

      AuthResult result = (await _auth.signInWithCredential(credential));
      FirebaseUser user = result.user;

      return user;
      
    } catch (error) {
      print(error);
      return null;
    }
  }

  // SignOut
  Future signOut() async {
    try {
      return await _auth.signOut(); <-- Should I do something different here for Apple?
    } catch (e) {
      print(e.toString());
      return null;
    }
  }
}

All the other apps logout correctly, but Apple doesnt. Should I do something different in the signout since it's using /routes?

Any help is much appreciated!!
Many thanks Joe

Answer 1

Should be fine, make sure that you have followed the steps described here:

https://firebase.google.com/docs/auth/ios/apple

Which means your application needs to fulfill the following requirements to make apple sign in work properly:

• Be a member of the Apple Developer Program
• Enable Sign In with Apple for your app on the Certificates, Identifiers & Profiles page of Apple's developer site.
• Enable Apple as a sign-in provider on firebase

Answer 2

await _firebaseAuth.signOut();

Use the above code for signout and check firebase IOS configuration