Expose MockUserCredential

Currently, if I want to mock the method User.linkWithProvider, which returns a UserCredential, I have to implement my own mock for UserCredential.

I'd prefer to simply re-use your implementation so I can have something like the following:

when(() => firebaseAuth.currentUser!.linkWithProvider(any()))
              .thenAnswer((_) async => Future.value(MockUserCredential(
                        mockUser: firebaseAuth.currentUser!,
              ));

Any reason why MockUserCredential shouldn't be exported and made available?

[atn832]

Despite the name, firebase_auth_mocks tries to fake as much as possible as you did so well in #91 (thanks btw!), so we don't want to use Mockito's pattern of mocking custom values.

Btw we don't export MockUserCredential and other custom implementations of the Firestore API because unit tests should use the public Firestore API as much as possible.

[ribeiro-gabriel]

@atn832 can you explane how to test some implementation which depends on signInWithEmailAndPassword method for instance?

I want to test my code but i can't mock the response of signInWithEmailAndPassword method

Edit: I was stuck in v0.9.2 because of some dependencies conflicts. So I made my own MockUser and MockUserCredetials classes based on this lib and it worked.