express-modern

https://github.com/magicdawn/express-modern

• 这个在strongloop自己的博文里的就是这个 https://strongloop.com/strongblog/async-error-handling-expressjs-es7-promises-generators/
• 还有一个包，https://github.com/Greenfields/express-async-wrap, express-async-wrap 只支持 async function. 当然你可以说 co.wrap(gen) 与 async function一样的啊~但是还是有点不一样的。co.wrap得到的function的形参个数是0的，对于express-handler来说，要判断是三个参数还是四个参数来决定是否去传err

于是就有了这个。

---

分割线，下面是README

express-modern

use async function or generator function with express

Install

npm i express-modern --save

API

const modern = require('express-modern');

generator function

const app = express();
app.get('/', modern(function * (req, res, next) {
  yield new Promise(r => setTimeout(r, 10));
  res.send('generator function');
}));

const res = yield request(app)
  .get('/')
  .endAsync();
res.text.should.match(/generator/);

the generator function will be wrap via co.wrap. and the modern function will take care of the arity of the handler. see http://expressjs.com/en/guide/error-handling.html

async function

const app = express();
app.get('/', modern(async function(req, res, next) {
  await new Promise(r => setTimeout(r, 10));
  res.send('async function');
}));

const res = yield request(app)
  .get('/')
  .endAsync();
res.text.should.match(/async/);

the async function will be called & the rejected value will be passed to next automatically

normal function

const app = express();
app.get('/', modern((req, res, next) => {
  res.send('normal function');
}));

const res = yield request(app)
  .get('/')
  .endAsync();

res.text.should.match(/normal/);

the modern function does nothing on normal function.

Changelog

CHANGELOG.md

License

the MIT License http://magicdawn.mit-license.org