Auth.auth().currentUser.isAnonymous is not correctly updated after linking Apple Login

[Johnson145]

Step 2: Describe your environment

• Objective C or Swift: Swift
• iOS version: 13.3
• Firebase SDK version: 6.6.2
• FirebaseUI version: 8.4.1
• CocoaPods Version: 1.8.4

Step 3: Describe the problem:

When migrating an anonymous user to a non-anonymous one by choosing the Login with Apple ID, the Auth.auth().currentUser.isAnonymous isn't updated and the attribute remains false.

Steps to reproduce:

1. (Programatically) log in with an anonymous user
2. Open the Firebase UI login screen with authUI.shouldAutoUpgradeAnonymousUsers = true
3. Log in with an Apple ID
4. Listen for the callback in func authUI(_ authUI: FUIAuth, didSignInWith authDataResult: AuthDataResult?, error: Error?)

Observed Results:

• Auth.auth().currentUser.isAnonymous is still true
• authDataResult?.user.isAnonymous is false

Expected Results:

• Auth.auth().currentUser.isAnonymous has the same value as the user provided in the callback parameter, i.e. it's false

Further notes

• When using other login methods, the two values are correctly synced.
• There used to be a similar issue (#651) for the email login.
• Not sure, whether this is a Firebase UI issue or a Firebase (Auth) issue in general.

[joeljfischer]

I haven't tested this myself, but I'm planning to support anonymous users and apple sign-in, so this would be a high priority request for myself as well. I'll comment again if I see the same issue.

[yuchenshi]

I've filed a bug internally as b/160627975.

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@joeljfischer This bug is about Auth.auth().currentUser.isAnonymous not being updated. However, linking an anon user with Apple Sign-in still works fine (minus this bug).

As OP mentioned, you just need to use authDataResult?.user.isAnonymous instead of Auth.auth().currentUser.isAnonymous for now to detect if a user has been upgraded or not for now. This workaround should be temporary and will not need be needed once we fix the bug.

[joeljfischer]

@yuchenshi Thank you for the clarification.