如何在Cloud Firestore中递增计数器

const firestore = require('@google-cloud/firestore');

// 初始化Cloud Firestore实例
const db = new firestore.Firestore();

// 定义集合和文档路径
const collectionPath = 'counters';
const documentPath = 'counter';

// 设置计数器的初始值
async function initializeCounter() {
  const docRef = db.collection(collectionPath).doc(documentPath);
  await docRef.set({ value: 0 });
}

// 递增计数器的值
async function incrementCounter() {
  const docRef = db.collection(collectionPath).doc(documentPath);
  await db.runTransaction(async (transaction) => {
    const doc = await transaction.get(docRef);
    const newValue = doc.data().value + 1;
    transaction.update(docRef, { value: newValue });
  });
}

// 获取计数器的值
async function getCounterValue() {
  const docRef = db.collection(collectionPath).doc(documentPath);
  const doc = await docRef.get();
  return doc.data().value;
}

// 示例用法
async function exampleUsage() {
  await initializeCounter();
  await incrementCounter();
  const counterValue = await getCounterValue();
  console.log('Counter value:', counterValue);
}

exampleUsage();