链接

自动化的处理Promise中的错误

  1. /**
  2.  * @description ### Returns Go / Lua like responses(data, err) 
  3.  * when used with await
  4.  *
  5.  * - Example response [ data, undefined ]
  6.  * - Example response [ undefined, Error ]
  7.  *
  8.  *
  9.  * When used with Promise.all([req1, req2, req3])
  10.  * - Example response [ [data1, data2, data3], undefined ]
  11.  * - Example response [ undefined, Error ]
  12.  *
  13.  *
  14.  * When used with Promise.race([req1, req2, req3])
  15.  * - Example response [ data, undefined ]
  16.  * - Example response [ undefined, Error ]
  17.  *
  18.  * @param {Promise} promise
  19.  * @returns {Promise} [ data, undefined ]
  20.  * @returns {Promise} [ undefined, Error ]
  21.  */
  22. // 这种处理方式来自于await-to-js
  23. const handle = (promise) => {
  24.   return promise
  25.     .then(data => ([data, undefined]))
  26.     .catch(error => Promise.resolve([undefined, error]));
  27. }
  29. async function userProfile() {
  30.   let [user, userErr] = await handle(getUser());
  32.   if(userErr) throw new Error('Could not fetch user details');
  34.   let [friendsOfUser, friendErr] = await handle(
  35.     getFriendsOfUser(userId)
  36.   );
  38.   if(friendErr) throw new Error('Could not fetch user\'s friends');
  40.   let [posts, postErr] = await handle(getUsersPosts(userId));
  42.   if(postErr) throw new Error('Could not fetch user\'s posts');
  44.   showUserProfilePage(user, friendsOfUser, posts);
  45. }