从 Firestore 侦听器返回零快照文档

Question

不知道为什么会这样。希望我能得到第二或第三双眼睛。请参阅代码中的注释。代码如下：

import Foundation
import Firebase

class FollowerApi {
    func loadFollowers(onSuccess: @escaping(_ followers: [Follower]) -> Void, newFollower: @escaping(Follower) -> Void, deleteFollower: @escaping(Follower) -> Void, listener: @escaping(_ listenerHandle: ListenerRegistration) -> Void) {
        
        guard let userId = Auth.auth().currentUser?.uid else { return }
        
        let listenerFirestore = Ref.FIRESTORE_COLLECTION_MY_FOLLOWERS.document(userId).collection("followers").order(by: "date", descending: false).addSnapshotListener { querySnapshot, error in
            
            guard let snapshot = querySnapshot else { return }
            
// this (snapshot.documentChanges.forEach) is where I am not 
// returning any documents! The breakpoint skips the switch 
// statement and hits the listener at the bottom of the file.

            snapshot.documentChanges.forEach { documentChange in
                                
                switch documentChange.type {
                
                case .added:
                    var followers = [Follower]()
                    let dict = documentChange.document.data()
                    guard let decodedFollower = try? Follower.init(fromDictionary: dict) else {
                        return
                    }
                    newFollower(decodedFollower)
                    followers.append(decodedFollower)
                    onSuccess(followers)
                    
                case .modified:
                    print("type: modified")
                    
                case .removed:
                    print("type: removed")
                    let dict = documentChange.document.data()
                    guard let decodedFollower = try? Follower.init(fromDictionary: dict) else {
                        return
                    }
                    deleteFollower(decodedFollower)
                }
            }
        }
        listener(listenerFirestore)
    }
}

我可以设置数据并将其发送到数据库，我可以看到我在那里清楚地有一个文档。但是 Xcode 控制台给了我这个：

有什么想法吗？

Answer 1

已解决

我在测试功能时有一个指向 3 个不同文档 ID 的集合。我有一个快照但返回零，因为数据库对返回的内容感到困惑。谢谢，弗兰克，与我们联系！