flutter_firebase_authentication_signin_email.dart

Future<bool> signInWithEmail(BuildContext context,
    {@required String email, @required String password}) {
  return _auth
      .signInWithEmailAndPassword(email: email, password: password)
      .then((result) {
    print("Welcome " + result.user.uid);
    Navigator.pop(context);
    Navigator.pushReplacement(
      context,
      MaterialPageRoute(
          builder: (context) => MainPage(
                user: result.user,
              )),
    );
    return true;
  }).catchError((e) {
    print(e);
    switch (e.code) {
      case "ERROR_WRONG_PASSWORD":
        print("Wrong Password! Try again.");
        break;
      case "ERROR_INVALID_EMAIL":
        print("Email is not correct!, Try again");
        break;
      case "ERROR_USER_NOT_FOUND":
        print("User not found! Register first!");
        Navigator.push(
          context,
          MaterialPageRoute(builder: (context) => RegisterWithEmail()),
        );
        break;
      case "ERROR_USER_DISABLED":
        print("User has been disabled!, Try again");
        break;
      case "ERROR_TOO_MANY_REQUESTS":
        print(
            "Sign in disabled due to too many requests from this user!, Try again");
        break;
      case "ERROR_OPERATION_NOT_ALLOWED":
        print(
            "Operation not allowed!, Please enable it in the firebase console");
        break;
      default:
        print("Unknown error");
    }
    return false;
  });
}