Auth::createUser* return different shape data than Firebase Web SDK

[brandonpearcy]

It seems like firebase-mock may be providing the wrong shape of return data for the suite of createUser* functions (or I'm misusing firebase-mock 😅) The difference is that firebase-mock is returning something that resembles firebase.User or firebase.UserInfo instead of firebase.auth.UserCredential.

I believe it should be returning data shaped like UserCredential, which has the UserInfo nested inside a user member.

Here are the relevant types from Firebase Auth (from the JS SDK).

    createUserWithEmailAndPassword(
      email: string,
      password: string
    ): Promise<firebase.auth.UserCredential>;

...where firebase.auth.UserCredential has the following shape:

  type UserCredential = {
    additionalUserInfo?: firebase.auth.AdditionalUserInfo | null;
    credential: firebase.auth.AuthCredential | null;
    operationType?: string | null;
    user: firebase.User | null;
  };

https://github.com/firebase/firebase-js-sdk/blob/master/packages/auth-types/index.d.ts#L314