Firebase如何一次性检索文档集合以及每个文档的子集合？

// 引入 Firebase SDK
import * as firebase from 'firebase/app';
import 'firebase/firestore';

// 初始化 Firebase 应用
const firebaseConfig = {
  apiKey: 'your-api-key',
  authDomain: 'your-auth-domain',
  projectId: 'your-project-id',
  storageBucket: 'your-storage-bucket',
  messagingSenderId: 'your-messaging-sender-id',
  appId: 'your-app-id'
};

firebase.initializeApp(firebaseConfig);
const db = firebase.firestore();

async function fetchCollections(db, collectionPath) {
  const collectionRef = db.collection(collectionPath);
  const snapshot = await collectionRef.get();

  const collections = [];

  snapshot.forEach(doc => {
    const data = doc.data();
    const document = { id: doc.id, ...data };

    collections.push(document);

    if (data.subCollections && data.subCollections.length > 0) {
      data.subCollections.forEach(subCollection => {
        collections.push(...fetchCollections(db, `${collectionPath}/${doc.id}/${subCollection}`));
      });
    }
  });

  return collections;
}

fetchCollections(db, 'your-collection-path').then(collections => {
  console.log(collections);
});