Google Sign In Flutter Web

main.dart

import 'package:google_sign_in/google_sign_in.dart';
import 'package:firebase_auth/firebase_auth.dart';

final GoogleSignIn _googleAuth = GoogleSignIn();
final FirebaseAuth _auth = FirebaseAuth.instance;

Future<dynamic> _signInWithGoogle({BuildContext ctx}) async {
    final GoogleSignInAccount googleUser = await _googleAuth.signIn();
    if (googleUser == null) {
      Scaffold.of(ctx).showSnackBar(SnackBar(
          action: SnackBarAction(
            label: 'Close',
            onPressed: () => Scaffold.of(ctx).hideCurrentSnackBar(),
          ),
          content: AutoSizeText('Canceled by user',
              maxLines: 1, style: TextStyle(fontSize: 14))));
      return;
    }
    final GoogleSignInAuthentication googleAuth =
        await googleUser.authentication;

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

    final FirebaseUser user =
        (await _auth.signInWithCredential(credential).catchError((e) {
      debugPrint(e);
    }))
            .user;
    return user;
  }