[App Crash] activeSurvey is null

[anandwana001]

 Fatal Exception: java.lang.IllegalArgumentException: Required value was null.
       at com.google.android.ground.ui.datacollection.DataCollectionViewModel.<init>(DataCollectionViewModel.kt:100)
       at com.google.android.ground.DaggerGroundApplication_HiltComponents_SingletonC$ViewModelCImpl$SwitchingProvider.get(DaggerGroundApplication_HiltComponents_SingletonC.java:1465)
       at dagger.hilt.android.internal.lifecycle.HiltViewModelFactory$2.createViewModel(HiltViewModelFactory.java:132)
       at dagger.hilt.android.internal.lifecycle.HiltViewModelFactory$2.create(HiltViewModelFactory.java:103)
       at dagger.hilt.android.internal.lifecycle.HiltViewModelFactory.create(HiltViewModelFactory.java:170)
       at androidx.lifecycle.ViewModelProvider$Factory.create(ViewModelProvider.android.kt:158)
       at androidx.lifecycle.viewmodel.ViewModelProviderImpl_androidKt.createViewModel(ViewModelProviderImpl.android.kt:34)
       at androidx.lifecycle.viewmodel.ViewModelProviderImpl.getViewModel$lifecycle_viewmodel_release(ViewModelProviderImpl.kt:65)
       at androidx.lifecycle.viewmodel.ViewModelProviderImpl.getViewModel$lifecycle_viewmodel_release$default(ViewModelProviderImpl.kt:47)
       at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.android.kt:91)
       at androidx.lifecycle.ViewModelLazy.getValue(ViewModelLazy.kt:51)
       at androidx.lifecycle.ViewModelLazy.getValue(ViewModelLazy.kt:35)
       at com.google.android.ground.ui.datacollection.DataCollectionFragment.getViewModel(DataCollectionFragment.kt:55)
       at com.google.android.ground.ui.datacollection.DataCollectionFragment.onViewCreated(DataCollectionFragment.kt:86)
       at androidx.fragment.app.Fragment.performViewCreated(Fragment.java:3152)
       at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:608)
       at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:286)
       at androidx.fragment.app.FragmentStore.moveToExpectedState(FragmentStore.java:114)
       at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1675)
       at androidx.fragment.app.FragmentManager.dispatchStateChange(FragmentManager.java:3259)
       at androidx.fragment.app.FragmentManager.dispatchViewCreated(FragmentManager.java:3170)
       at androidx.fragment.app.Fragment.performViewCreated(Fragment.java:3153)
       at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:608)
       at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:286)
       at androidx.fragment.app.FragmentStore.moveToExpectedState(FragmentStore.java:114)
       at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1675)
       at androidx.fragment.app.FragmentManager.dispatchStateChange(FragmentManager.java:3259)
       at androidx.fragment.app.FragmentManager.dispatchActivityCreated(FragmentManager.java:3177)
       at androidx.fragment.app.FragmentController.dispatchActivityCreated(FragmentController.java:263)
       at androidx.fragment.app.FragmentActivity.onStart(FragmentActivity.java:350)
       at androidx.appcompat.app.AppCompatActivity.onStart(AppCompatActivity.java:251)
       at com.google.android.ground.AbstractActivity.onStart(AbstractActivity.kt:53)
       at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1455)
       at android.app.Activity.performStart(Activity.java:8105)
       at android.app.ActivityThread.handleStartActivity(ActivityThread.java:3745)
       at android.app.servertransaction.TransactionExecutor.performLifecycleSequence(TransactionExecutor.java:222)
       at android.app.servertransaction.TransactionExecutor.cycleToPath(TransactionExecutor.java:202)
       at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:174)
       at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:98)
       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2289)
       at android.os.Handler.dispatchMessage(Handler.java:106)
       at android.os.Looper.loopOnce(Looper.java:201)
       at android.os.Looper.loop(Looper.java:288)
       at android.app.ActivityThread.main(ActivityThread.java:7996)
       at java.lang.reflect.Method.invoke(Method.java)
       at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:553)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)
        

[gino-m]

This crash occurerd 20 times in the last 30 days, all from DataCollectionViewModel, but with no crash keys set. This implies that the crash occurred outside of the normal app lifecycle, perhaps after a draft was restored after the app was killed. Filing as P1.

[gino-m]

The crash occurs here:

  private val activeSurvey: Survey = requireNotNull(surveyRepository.activeSurvey)

This sounds like a race condition because we're using a synchronous call to activeSurvey, which may not have been initialized yet when the view is being restored. Likely happening after the app is killed and restarted during data collection.

[kenstershiro]

Suggestion from @gino-m for the race condition, given the load from db should be very fast, it's ok to block the UI to wait for this for now.

[gino-m]

@anandwana001 That might look something like this:

 private val activeSurvey: Survey = runBlocking { surveyRepository.activeSurveyFlow.filterNotNull().first() }