如何使用云函数返回firestore中的每个集合及其文档？

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();

// 云函数入口函数
exports.getFirestoreData = functions.https.onRequest(async (req, res) => {
  try {
    const collections = await admin.firestore().listCollections();
    
    const result = [];
    for (const collection of collections) {
      const collectionData = await collection.get();
      const documents = [];
      collectionData.forEach((doc) => {
        documents.push(doc.data());
      });
      result.push({ collection: collection.id, documents: documents });
    }
    
    res.status(200).json(result);
  } catch (error) {
    console.error(error);
    res.status(500).send('Internal Server Error');
  }
});