I'm getting an error “Error type 'AuthResult' is not a subtype of type 'FirebaseUser' in type cast” when I'm trying to login or signup

Question

I\'m making a flutter app for my college project, where I\'m adding a login and signup page and authenticating it via Firebase, and when I click login the debug console says

Answer 1

I had same error and changed code to:

FirebaseUser user = (await _firebaseAuth.signInWithEmailAndPassword(email: email, password: password)).user;

The app works as expected on a real device, without an error in the console, but Visual Studio Code shows red underline at the end below user and outputs an error:

The getter 'user' isn't defined for the class 'FirebaseUser'. Try importing the library that defines 'user', correcting the name to the name of an existing getter, or defining a getter or field named 'user'.

[Solution] Restart VS Code. VS Code uses the old library until restart.

Answer 2

It has been changed what you should do is AuthResult result = await _firebaseAuth.signInWithEmailAndPassword( email: email, password: password); FirebaseUser user = result.user;

Answer 3

• use User instead of FirebaseUser on firebase_auth 0.18.0+1

  final User user = (await FirebaseAuth.instance.signInWithEmailAndPassword(
                  email: 'abc@gmail.com',
                  password: 'abc',
                 )).user;
  

Answer 4

signInWithEmailAndPassword returns AuthResult and AuthResult class contains instance variable user of type FirebaseUser. So You have to change your code as following way.

FirebaseUser userDetails = (await FirebaseAuth.instance
          .signInWithEmailAndPassword(Credentialsxxx)).user;
print('sign in : ${userDetails.uid}');

Answer 5

I face the same issue. Just modify to be:

final FirebaseUser user = (await _auth.signInWithCredential(credential)).user;

See https://github.com/flutter/flutter/issues/38757#issuecomment-522307525

Answer 6

This is a breaking change in the plugin and its documented here https://pub.dev/packages/firebase_auth#0120

So you shouldn't do any type of casting you just have to refactor your code to adopt the new changes :

FirebaseUser user = (await FirebaseAuth.instance.
signInWithEmailAndPassword(email: email, password: password))
.user;