[auth]: web-context-already-presented error on Android due to android:taskAffinity=""

[passsy]

Is there an existing issue for this?

• I have searched the existing issues.

Which plugins are affected?

Auth

Which platforms are affected?

Android

Description

This is a followup to the closed/locked issue #13297 which I ran into. The chrome custom tab disappears when I switch apps (e.g. to open my password manager) and opening the login again returns the error web-context-already-presented.

copy_1864E306-A54C-4C93-9C1D-9D63FF9AA559.MOV

The solution to that is mentioned here: MaikuB/flutter_appauth#503 (comment)

Remove android:taskAffinity="" from the AndroidManifest.xml

---

The firebase_auth sdk should detect this, and show a waning

Reproducing the issue

Reproducible in the firebase_auth example application https://github.com/firebase/flutterfire/tree/main/packages/firebase_auth/firebase_auth/example

Using signInWithProvider.

import 'package:firebase_auth/firebase_auth.dart';
import 'package:flutter/material.dart';

class SampleScreen extends StatelessWidget {
  const SampleScreen({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: ElevatedButton(
          child: const Text("Login"),
          onPressed: () async {
            final provider = TwitterAuthProvider(); // or any other that opens a webview
            await FirebaseAuth.instance.signInWithProvider(provider);
          },
        ),
      ),
    );
  }
}

Firebase Core version

3.13.0

Flutter Version

3.24.5

Relevant Log Output

Flutter dependencies

No response

Additional context and comments

No response

[SelaseKay]

Hi @passsy, thanks for the report! This looks like an issue that belongs to the Firebase Android SDK rather than FlutterFire. Since firebase_auth is a wrapper around the native SDK, the best place to request this feature would be in the Firebase Android SDK repository. The best we can do is have this added to our documentation.

[passsy]

This primarily affects Flutter apps because android:taskAffinity="" is in Flutter's default template but not in native Android projects.
If the Firebase Android SDK can detect this programmatically, that would be ideal. Otherwise, adding a note to the FlutterFire documentation would help, since that's where affected developers typically look for guidance rather than the native Android SDK docs.

[SelaseKay]

You're right. We'll add a documentation to inform users about this. That seems more straightforward.