如何在云函数firestore查询上返回承诺

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

const db = admin.firestore();

exports.queryFirestore = async (req, res) => {
  try {
    const collectionRef = db.collection('your_collection'); // 替换为实际的集合名称
    const querySnapshot = await collectionRef.get();
    
    const data = [];
    querySnapshot.forEach((doc) => {
      data.push(doc.data());
    });
    
    res.status(200).json(data);
  } catch (error) {
    console.error('Error querying Firestore:', error);
    res.status(500).send('Error querying Firestore');
  }
};