一、使用Promise,别使用Callbacks

Callbacks不够简洁，它会产生大量的嵌套。在ES6中，最好使用Promises

Bad:import { get } from 'request';import { writeFile } from 'fs';get('https://en.wikipedia.org/wiki/Robert_Cecil_Martin', (requestErr, response) => {  if (requestErr) {    console.error(requestErr);  } else {    writeFile('article.html', response.body, (writeErr) => {      if (writeErr) {        console.error(writeErr);      } else {        console.log('File written');      }    });  }});Good:import { get } from 'request';import { writeFile } from 'fs';get('https://en.wikipedia.org/wiki/Robert_Cecil_Martin')  .then((response) => {    return writeFile('article.html', response);  })  .then(() => {    console.log('File written');  })  .catch((err) => {    console.error(err);  });

 二、Async/Await 比Promises更简洁

Promises比callbacks简洁很多，但 ES2017/ES8 提出了async/await 方法，提供了更简洁的解决办法。你只需要在函数前面加一个 async关键字，然后就可以不用then链式方法写逻辑了。如果能用 ES2017/ES8现在就开始用吧。

Bad:import { get } from 'request-promise';import { writeFile } from 'fs-promise';get('https://en.wikipedia.org/wiki/Robert_Cecil_Martin')  .then((response) => {    return writeFile('article.html', response);  })  .then(() => {    console.log('File written');  })  .catch((err) => {    console.error(err);  });Good:import { get } from 'request-promise';import { writeFile } from 'fs-promise';async function getCleanCodeArticle() {  try {    const response = await get('https://en.wikipedia.org/wiki/Robert_Cecil_Martin');    await writeFile('article.html', response);    console.log('File written');  } catch(err) {    console.error(err);  }}