Documentation: Can't recreate default Firebase App

[kvanry]

Describe your environment

• Android Studio version: 3.4.2
• Firebase Component: Database
• Component version: 19.1.0

Describe the problem

Caused by java.lang.IllegalStateException
FirebaseApp was deleted
com.google.android.gms.common.internal.Preconditions.checkState (Preconditions.java:9)
com.google.firebase.FirebaseApp.checkNotDeleted (FirebaseApp.java:509)
com.google.firebase.FirebaseApp.getName (FirebaseApp.java:182)
com.google.firebase.auth.internal.zzv.<init> (zzv.java:54)
com.google.firebase.auth.internal.zzas.<init> (zzas.java:6)
com.google.firebase.auth.FirebaseAuth.zzct (FirebaseAuth.java:9)
com.google.firebase.auth.FirebaseAuth.addIdTokenListener (FirebaseAuth.java:8)
com.google.firebase.database.android.AndroidAuthTokenProvider$1.addTokenChangeListener (AndroidAuthTokenProvider.java:57)
com.google.firebase.database.core.Repo.deferredInitialization (Repo.java:110)
com.google.firebase.database.core.Repo.access$000 (Repo.java:56)
com.google.firebase.database.core.Repo$1.run (Repo.java:95)
java.util.concurrent.Executors$RunnableAdapter.call (Executors.java:458)
java.util.concurrent.FutureTask.run (FutureTask.java:266)
java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run (ScheduledThreadPoolExecutor.java:301)
java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1167)
java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:641)
java.lang.Thread.run (Thread.java:764)

And

Fatal Exception: java.lang.RuntimeException
Uncaught exception in Firebase Database runloop (3.0.0). Please report to [email protected]
com.google.firebase.database.android.AndroidPlatform$1$1.run (AndroidPlatform.java:96)
android.os.Handler.handleCallback (Handler.java:873)
android.os.Handler.dispatchMessage (Handler.java:99)
android.os.Looper.loop (Looper.java:205)
android.app.ActivityThread.main (ActivityThread.java:6983)
java.lang.reflect.Method.invoke (Method.java)
com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run (RuntimeInit.java:493)
com.android.internal.os.ZygoteInit.main (ZygoteInit.java:884)

Steps to reproduce:

We haven't been able to pinpoint how this is occuring, however our setup is we dynamically can switch between firebase environments. We've spent a few days trying to replicate, unfortunately only our customers are finding this issue.

Relevant Code:

    private fun updateFirebase(environment: Environment) {
        firebaseApp?.delete()

        when (environment) {
            Environment.Unknown,
            Environment.NotSet -> { /* We don't need to do anything here */
                return
            }
            Environment.Dev -> {
                FirebaseApp.initializeApp(context, AppConfiguration.instance.firebaseDev)
            }
            Environment.Staging -> {
                FirebaseApp.initializeApp(context, AppConfiguration.instance.firebaseStage)
            }
            Environment.Prod -> {
                FirebaseApp.initializeApp(context, AppConfiguration.instance.firebaseProd)
            }
            Environment.Europe -> {
                FirebaseApp.initializeApp(context, AppConfiguration.instance.firebaseEurope)
            }
        }
        
        FirebaseDatabase.getInstance().setPersistenceEnabled(false)
    }

[rlazo]

/cc @schmidt-sebastian

[kvanry]

In the meantime is there anything we can do to mitigate this issue as it's affecting a large percentage of our users?

[schmidt-sebastian]

@kvanry Sorry for not getting back to you earlier.

It looks like you are deleting the default app and attempting to replace it with a new FirebaeApp. To do this properly, you will have to manually pass in the new app into the FirebaseDatabase.getInstance() call (getInstance() will become getInstance(app)).

Can you try this? I believe your error should then go away.

[kvanry]

I mean, yes we can try this, that being said if that is the fix, I feel like it should be more clear that if you delete the default app that this is necessary, either in documentation or if the error that is thrown could be more descriptive. Otherwise the assumption is that the new default app becomes the new FirebaseApp instance.

[schmidt-sebastian]

Moving this to the core component to get the docs fixed.

[ashwinraghav]

This has an explanation of why it is tricky to implement delete effectively
#66 (comment)

[ashwinraghav]

Just wanted to drop a note that our efforts are generally focussed only on APIs that are publicly documented. The delete API is currently not supported for these sorts of reasons.

I'll leave this open as a feature request though.

https://github.com/firebase/firebase-android-sdk/blob/master/firebase-common/src/main/java/com/google/firebase/FirebaseApp.java#L308-L315