[Bug] Auth Unity SDK still requires Google Play Services while Android SDK does not

[MohsenneChaverdie]

Issue details:

• Unity editor version: 2019.2.21f1
• Firebase Unity SDK version: 7.1.0
• Source you installed the SDK: unitypackage
• Problematic Firebase Component: Auth
• Other Firebase Components in use: Firestore
• Platform you are using the Unity editor on: Windows
• Platform you are targeting: Oculus Quest 2
• Scripting Runtime: Mono

Issue description:

Trying to authenticate with Firebase through the Auth Unity package. In Unity Editor and Android with Google Services it works, however on Android devices without Google services, like Oculus Quest 2, or Emulator (No google API) does not work.
On pure Android, through Android Studio, the Authentication does not need Google play services. So why the Unity Auth Package still requires Google API?

Steps to reproduce:

Have you been able to reproduce this issue with just the Firebase Unity quickstarts (this GitHub project)? Yes. I have tried the Auth example.

What's the issue repro rate? 100%

What happened? How can we make the problem occur?
Try a simple Unity scene with authentication on an Android without Google play services. It can never authenticate itself.

On which documentation page have you seen that Google Play Services for Authentication is not required anymore?
https://firebase.google.com/docs/android/android-play-services

[chkuang-g]

@MohsenneChaverdie

Could you provide the log when the device failed to authenticate? That would help us to quickly identify the issue.

I suspect it is because C++ SDK is still checking if Google Play Services is available while the Android SDK it wraps around actually does not need it anymore. See this code.

If this is the case, you should see FirebaseApp.CheckAndFixDependenciesAsync() failed.

The Android public doc said that com.google.firebase:firebase-auth:20.0.3 does not requires Google Play Service. However, Firebase Unity SDK 7.1.0 is using com.google.firebase:firebase-auth:20.0.2. I think that version probably does not require GPS either but I need to confirm with the team.

I think this is a valid bug. Thanks for reporting it.

[MohsenneChaverdie]

@chkuang-g thank you very much for your reply.

Yes exactly. I see the FirebaseApp.CheckAndFixDependenciesAsync() fails on Android without Google Play Services.

Someone on Twitter apparently is very sure that at this time due to architectural problems, it is not possible.

[chkuang-g]

@MohsenneChaverdie Thanks for your response. I'll contact the team about this.

[StephenHodgson]

I'm also blocked by this as well.