Firebase异步任务到协程

import com.google.firebase.firestore.FirebaseFirestore
import kotlinx.coroutines.*
import kotlin.coroutines.resume
import kotlin.coroutines.suspendCoroutine

suspend fun getDocumentAsync(collectionPath: String, documentId: String): Map<String, Any>? {
    return suspendCoroutine { continuation ->
        FirebaseFirestore.getInstance().collection(collectionPath).document(documentId)
            .get()
            .addOnCompleteListener { task ->
                if (task.isSuccessful) {
                    val document = task.result
                    if (document != null) {
                        continuation.resume(document.data)
                    } else {
                        continuation.resume(null)
                    }
                } else {
                    continuation.resumeWithException(task.exception!!)
                }
            }
    }
}

fun main() = runBlocking {
    val document = getDocumentAsync("users", "user123")
    println(document)
}