使用Promises更好地处理错误?

时间:2018-05-16 14:46:15

标签: javascript error-handling promise

我目前正在尝试使用Google Firebase功能来访问Google API。它运行正常,但我在尝试管理可以检测到的错误时有点迷失......

.HTTPS getGoogleUsers函数中,我想返回HTTP状态代码(200或错误代码),以及数据(或错误消息)

据我所知,我可能会收到错误:

    来自connect()功能的
  • (500:内部服务器错误或401未经授权)

  • 来自listUsers()功能的
  • (500:内部服务器错误或400错误请求)

我完全或部分错了吗?在这种情况下我的策略应该是什么? 感谢您的反馈..

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

const {google} = require('googleapis');
const KEY = require('./service-key.json');

 // Create JSON Web Token Client
 function connect () {
  return new Promise((resolve, reject) => {
    const jwtClient = new google.auth.JWT(
      KEY.client_email,
      null,
      KEY.private_key,
      ['https://www.googleapis.com/auth/admin.directory.user'],
      'adminuser@mydomain.com'
    );
    jwtClient.authorize((err) => {
      if(err) {
        reject(err);
      } else {
        resolve(jwtClient);
      }
    });
  });
}

function listUsers (client) {
  return new Promise((resolve, reject) => {
    google.admin('directory_v1').users.list({
      auth: client,
      domain: 'mydomain.com',
    }, (err, response) => {
      if (err) {
        reject(err);
      }
      resolve(response.data.users);
    });
  });
}

function getAllUsers () {
  connect()
    .then(client => {
      return listUsers(client);
    })
    .catch(error => {
      return error;
    })
}
exports.getGoogleUsers = functions.https.onRequest((req, res) => {
  const users = getAllUsers();
  if (error) {
     status = error.status;
     data = error.message;
  } else {
    status = 200;
    data = users;
  }
  res.send({ status: status, datas: data })
});

1 个答案:

答案 0 :(得分:0)

我认为你在寻找

function getAllUsers () {
  return connect().then(listUsers);
//^^^^^^
}

exports.getGoogleUsers = functions.https.onRequest((req, res) => {
  getAllUsers().then(users => {
    return {status: 200, datas: users};
  }, error => {
    return {status: error.status, datas: error.message};
  }).then(response => {
    res.send(response);
  });
});

这使用the .then(…, …) method with two callbacks来区分成功和错误情况,并等待承诺的结果。