将firebase链接方法重写为promise.all

<script src="https://www.gstatic.com/firebasejs/9.0.2/firebase-app.js"></script>
<script src="https://www.gstatic.com/firebasejs/9.0.2/firebase-database.js"></script>

const firebaseConfig = {
  // Firebase配置信息
};

firebase.initializeApp(firebaseConfig);
const database = firebase.database();

function linkFirebaseNodes() {
  const node1Ref = database.ref('node1');
  const node2Ref = database.ref('node2');

  const node1Promise = new Promise((resolve, reject) => {
    node1Ref.on('value', (snapshot) => {
      resolve(snapshot.val());
    }, (error) => {
      reject(error);
    });
  });

  const node2Promise = new Promise((resolve, reject) => {
    node2Ref.on('value', (snapshot) => {
      resolve(snapshot.val());
    }, (error) => {
      reject(error);
    });
  });

  return Promise.all([node1Promise, node2Promise]);
}

linkFirebaseNodes()
  .then((results) => {
    const node1Data = results[0];
    const node2Data = results[1];
    // 处理返回的数据
  })
  .catch((error) => {
    // 处理错误
  });