Undefined class 'AuthResult' in Flutter

I have been trying to implement Google login screen using Flutter.

```dart
final AuthResult authResult = await _auth.signInWithCredential(credential);
```

The editor, for the line above, says:

> Undefined class 'AuthResult'

How can I fix it? Any help would be very appreciated.

The problem was firebase_auth version that I added to *pubspec.yaml*.

Previous version I have been using:
`firebase_auth: ^0.11.1+8`

Now: `firebase_auth: ^0.15.2`

This change on versions has fixed the problem.

They renamed the class `AuthResult` to `UserCredential`

Starting from Version firebase_auth 0.18.0:
-------------------------------------------

`FirebaseUser` has been changed to `User`

`AuthResult` has been changed to `UserCredential`

`GoogleAuthProvider.getCredential()` has been changed to `GoogleAuthProvider.credential()`

`onAuthStateChanged` which notifies about changes to the user's sign-in state was replaced with `authStateChanges()`

`currentUser()` which is a method to retrieve the currently logged in user, was replaced with the property `currentUser` and it no longer returns a `Future<FirebaseUser>`

In 2020 firebase_Auth_version(0.18.3+1), they changed from `AuthResult` to `UserCredential`, and `GetCredentials` deprecated to `credentials`.

**`AuthResult`** has been changed to **`UserCredential`**

In 2021 firebase_auth_version of ^3.0.1,
**AuthException** has also been change to **FirebaseAuthException**

```
final UserCredential authResult = await _auth.signInWithCredential(credential);
```