Usefull Firebase Kotlin suspend stuff

GoogleApiExtensions.kt

import com.google.android.gms.tasks.Task
import com.google.firebase.auth.AuthResult
import com.google.firebase.auth.FirebaseAuth
import com.google.firebase.firestore.CollectionReference
import com.google.firebase.firestore.DocumentReference
import com.google.firebase.storage.CancellableTask
import kotlinx.coroutines.ExperimentalCoroutinesApi
import kotlinx.coroutines.channels.awaitClose
import kotlinx.coroutines.channels.sendBlocking
import kotlinx.coroutines.flow.callbackFlow
import kotlinx.coroutines.suspendCancellableCoroutine
import kotlin.coroutines.resume
import kotlin.coroutines.resumeWithException

suspend fun <T> Task<T>.suspend() = suspendCancellableCoroutine<T> { continuation ->
    this.addOnCompleteListener {
        if (it.isSuccessful) {
            continuation.resume(it.result!!)
        } else {
            continuation.resumeWithException(it.exception!!)
        }
    }
    continuation.invokeOnCancellation {
        if (this is CancellableTask) { this.cancel() }
    }
}

@ExperimentalCoroutinesApi
fun DocumentReference.asFlow() = callbackFlow {
    val subscription = [email protected] { value, error ->
        if (value != null) sendBlocking(value)
        else if (error != null) throw error
    }
    awaitClose { subscription.remove() }
}

@ExperimentalCoroutinesApi
fun CollectionReference.asFlow() = callbackFlow {
    val subscription = [email protected] { value, error ->
        if (value != null) sendBlocking(value)
        else if (error != null) throw error
    }
    awaitClose { subscription.remove() }
}

@ExperimentalCoroutinesApi
fun currentFirebaseUser() = callbackFlow {
    val listener = FirebaseAuth.AuthStateListener {
        sendBlocking(it)
    }
    authentication.addAuthStateListener(listener)
    awaitClose { authentication.removeAuthStateListener(listener) }
}