Firestore控制台日志输出中的意外行为

我决定进行从实时数据库到Firestore的过渡，但是我遇到了一些意外的问题。这很简单：浏览器控制台会注销极其出乎意料的结果，但是像现存的方法仍然可以按预期工作。

const firebase = require('firebase/app');
require('firebase/firestore');

const firebaseConfig = {
   the usual
};

firebase.initializeApp(firebaseConfig);

const firestore = firebase.firestore();

(async () => {
    const userRef = firestore.doc('users/fjafSAe2VQRWx7g9ocxn')
    const snapShot = await userRef.get();
    console.log(snapShot)
    console.log(snapShot.exists)
})()

现在console.log在浏览器中显示出一些我不明白的胡言乱语：

t {pf: e, w_: t, Nf: n, Ff: false, $f: false, …}
$f: false
Ff: false
Nf: n {key: t, version: t, nn: t, Ye: false, hasCommittedMutations: false}
m_: null
pf: e {cf: n, uf: e, hf: FirebaseAppImpl, lf: e, INTERNAL: {…}, …}
w_: t {path: n}
exists: (...)
id: (...)
metadata: (...)
ref: (...)
__proto__: Object

但是snapShot.exists可以按预期工作。甚至更奇怪的是，当我在Node.js中进行控制台登录时，它会输出DocumentSnapshot

DocumentSnapshot {
  _firestore:
   Firestore {
     _offlineComponentProvider:
      MultiTabOfflineComponentProvider { onlineComponentProvider: OnlineComponentProvider {} },
     _onlineComponentProvider: OnlineComponentProvider {},
     _firebaseApp:
      FirebaseAppImpl {
        firebase_: [Object],
        isDeleted_: false,
        name_: '[DEFAULT]',
        automaticDataCollectionEnabled_: false,
        options_: [Object],
        container: [ComponentContainer] },
     _queue:
      AsyncQueue {
        tail: [Promise],
        retryableOps: [],
        _isShuttingDown: false,
        delayedOperations: [Array],
        failure: null,
        operationInProgress: true,
        timerIdsToSkip: [],
        backoff: [ExponentialBackoff],
        visibilityHandler: [Function] },
     INTERNAL: { delete: [Function: delete] },
     _databaseId:
      DatabaseId { projectId: 'ecommerce-33931', database: '(default)' },
     _persistenceKey: '[DEFAULT]',
     _credentials:
      FirebaseCredentialsProvider {
        tokenListener: [Function],
        currentUser: [User],
        receivedInitialUser: true,
        tokenCounter: 1,
        changeListener: [Function],
        forceRefresh: false,
        auth: null },
     _settings:
      FirestoreSettings {
        host: 'firestore.googleapis.com',
        ssl: true,
        credentials: undefined,
        timestampsInSnapshots: true,
        ignoreUndefinedProperties: false,
        cacheSizeBytes: 41943040,
        experimentalForceLongPolling: false },
     _firestoreClient:
      FirestoreClient {
        credentials: [FirebaseCredentialsProvider],
        asyncQueue: [AsyncQueue],
        clientId: 'exM4ONFeK4q2tpdTjiyl',
        initializationDone: [Deferred],
        databaseInfo: [DatabaseInfo],
        persistence: [MemoryPersistence],
        sharedClientState: [MemorySharedClientState],
        localStore: [LocalStoreImpl],
        gcScheduler: null,
        datastore: [DatastoreImpl],
        remoteStore: [RemoteStoreImpl],
        syncEngine: [SyncEngineImpl],
        eventMgr: [EventManagerImpl] } },
  _key:
   DocumentKey { path: ResourcePath { segments: [Array], offset: 0, len: 2 } },
  _document:
   Document {
     key: DocumentKey { path: [ResourcePath] },
     version: SnapshotVersion { timestamp: [Timestamp] },
     objectValue: ObjectValue { proto: [Object] },
     hasLocalMutations: false,
     hasCommittedMutations: false },
  _fromCache: false,
  _hasPendingWrites: false,
  _converter: null }

但是，existing属性未在此处列出（但仍记录为true）。知道是什么原因造成的吗？我在React中工作，当它不起作用时，也可以在Node中尝试它。