Permission Denied Error in Android Emulator when Enforcing App Check for Flutter App - flutter

Question

After spending hours for getting App Check working on the physical devices (iOS and Android) of my Flutter app i also tried the provided documentation steps in order to get it working for Android emulator as well.
Whatever i try i always get the following error for all my listening streams that are invoked against the Firestore database when App Check is enforced:
W/Firestore( 5612): (24.1.2) [Firestore]: Listen for Query(target=Query(Contract where isArchive==false and contractorId==myContractorId order by __name__);limitType=LIMIT_TO_FIRST) failed: Status{code=PERMISSION_DENIED, description=Missing or insufficient permissions., cause=null}
I've added the depencency in app/build.gradle:
dependencies {
implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
implementation 'com.google.firebase:firebase-appcheck-debug:16.0.0'
}
and have overridden onCreate in MainActivity.kt:
class MainActivity: FlutterActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
if (BuildConfig.DEBUG) {
//Log.d("MainActivity", "debug mode entered")
FirebaseApp.initializeApp( /*context=*/this)
val firebaseAppCheck: FirebaseAppCheck = FirebaseAppCheck.getInstance()
firebaseAppCheck.installAppCheckProviderFactory(DebugAppCheckProviderFactory.getInstance())
} else {
//Log.d("MainActivity", "else mode entered")
}
super.onCreate(savedInstanceState)
}
}
The resulting debug token was added successfully to the list of debug tokens in Firebase console.
All Firestore collection rules look like the following example rule:
match /Contractor/{contractor} {
allow read, write: if request.auth.uid != null;
}
Activating App Check in the Flutter main function looks like this:
await Firebase.initializeApp(options: DefaultFirebaseOptions.currentPlatform);
await FirebaseAppCheck.instance.activate();
Without enforced App Check i don't have any problems running the Flutter app on my Android emulator.
All Firebase plugins are the most recent ones.
What else can i try or change in order to get this working?
If it doesn't work also on Android emulators we will give up using App Check.

Answer 1

Have you added this in cloud function:
if (context.app == undefined && !process.env.FUNCTIONS_EMULATOR) {
throw new functions.https.HttpsError(
"failed-precondition",
"The function must be called from an App-Check verified app.");
}
You need to add this code:
!process.env.FUNCTIONS_EMULATOR