ExpressJS Async Functions

A dead simple ~~ES6 generators and~~ ES7 async/await support hack for ExpressJS

Forked from express-yields so that it has just ES7 async/await support and none for ES6 generators. The latter depends on co which is a relatively heavy install.

Usage

npm install express-async-functions --save

Then require this script somewhere before you start using it:

const express = require('express');
require('express-async-functions');
const User = require('./models/user');
const app = express();

app.get('/users', async (req, res) => {
  const users = await User.findAll(); // <- some Promise
  res.send(users);
});

A Notice About Calling next

As we all know express sends a function called next into the middleware, which then needs to be called with or without error to make it move the request handling to the next middleware. If you want to pass an error, just throw a normal exception:

app.use(async (req, res) => {
  const user = await User.findByToken(req.get('authorization'));

  if (!user) throw Error("access denied");
});

How Does This Work?

This is a minimalistic and unobtrusive hack. Instead of patching all methods on an express Router, it wraps the Layer#handle property in one place, leaving all the rest of the express guts intact.

The idea is that you require the patch once and then use the 'express' lib the usual way in the rest of your application.

Copyright & License

What? I forked this from express-yields. And removed the generators stuff. Dunno.