I am testing authentication with a mobile app. I am using Firebase's authentication service. I tested it once before using an Android device, and would like to test it again.

The first time I tested it, it followed the steps I wanted it to do. The steps are as follows:

1. The app launches the authentication screen (FirebaseUI Auth)
2. If it is the first time the user has logged in, it will bring them to a fragment screen for them to create their Username
3. Otherwise, it will bring them to the main screen.

The code for this is below:

class LoginFragment: Fragment() {

    private val TAG = "LoginFragment"

    private var _binding: FragmentLoginBinding? = null
    private val binding
        get() = checkNotNull(_binding) {
            "Cannot access binding because it is null, is the view visible?"
        }

    private val loginViewModel: LoginViewModel by viewModels()

    // Creates ActivityResultLauncher to register a callback for FirebaseUI Activity result contract
    private val signInLauncher = registerForActivityResult(
        FirebaseAuthUIActivityResultContract(),
    ) { res ->
        this.onSignInResult(res)
    }

    // Authentication providers
    val providers = arrayListOf<AuthUI.IdpConfig>(
        AuthUI.IdpConfig.EmailBuilder().build(),
        AuthUI.IdpConfig.GoogleBuilder().build()
    )

    //creates custom layout
    val customLayout = AuthMethodPickerLayout.Builder(R.layout.fragment_login)
        .setGoogleButtonId(R.id.google_sign_in)
        .setEmailButtonId(R.id.email_sign_in)
        .build()

    // Creates and launches sign-in intent
    val signInIntent = AuthUI.getInstance()
        .createSignInIntentBuilder().setAvailableProviders(providers)
        .setIsSmartLockEnabled(false, true).setAuthMethodPickerLayout(customLayout).build()


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

    }

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        _binding = FragmentLoginBinding.inflate(inflater, container, false)
        return binding.root
    }


    override fun onStart() {
        super.onStart()
        val currentUser = FirebaseAuth.getInstance().currentUser
        if (currentUser == null) {
            signInLauncher.launch(signInIntent)
        } else {
            Log.e("Auth", "onStart action_login_to_mainline")
            findNavController().navigate(R.id.action_login_to_mainline)
        }
    }

override fun onDestroyView() {
    super.onDestroyView()
    _binding = null
}


fun onSignInResult(result: FirebaseAuthUIAuthenticationResult) {
    val response = result.idpResponse
    if (result.resultCode == RESULT_OK) {
        //successfully signed in, set up username if first time logging in
        //TODO: if user has already signed in, redirect to login with a message
        val user = FirebaseAuth.getInstance().currentUser
        val db = FirebaseFirestore.getInstance()
        db.collection("users").document(user!!.uid).get()
            .addOnSuccessListener { document ->
                if (!document.exists()) {
                    // User doesn't exist in Firestore, treat as new user
                    Log.d("Auth", "User not found in Firestore, navigating to username setup")
                    findNavController().navigate(R.id.action_login_to_setusername)
                } else {
                    // User exists in Firestore, proceed to main screen
                    Log.d("Auth", "User found in Firestore, navigating to main")
                    findNavController().navigate(R.id.action_login_to_mainline)
                }
            }
            .addOnFailureListener { e ->
                Log.e("Auth", "Error checking user existence: ${e.message}", e)
                // Important: Add navigation to username setup here as fallback
                findNavController().navigate(R.id.action_login_to_setusername)
            }
    }
}

}

All 3 steps were successfully followed the first time I tested it. I changed a few things UI wise and would like to test it again, but step 2 is being skipped. It is happening at onStart(), and it is executing the else when I want it to execute the if. How do I fix this?

This is what I have tried to prevent step 2 from being skipped:

• Factory reset my device
• Cleared the Authentication and Firestore Databases on google cloud console
• Only allowed the user to get to the mainline if their information was in the firestore database

I am deleting the app on my device each time I try to test it. I am certain there is nothing stored in the database or the authenticator as it is showing as empty on google cloud platform. If any more information is needed please let me know! I'm lost as to what to do.

I tried logging in both with Google and with Email, both times the second step was skipped no matter if I used a different Google account or Email address.