express-coroutine

Generator function and Async function to be used as middlewares in express like koa. ( use lei-coroutine )

Installation

npm install express-coroutine --save

Usage

Init express

const express = require('express-coroutine')(require('express'));
const app = express();

Init router

const express = require('express-coroutine')(require('express'));
const app = express();
const router = new express.Router();
app.use(router);
router.get('/', function* (req, res) {
  res.send('it works!');
});
// also async function
router.get('/', async function (req, res) {
  res.send('it works!');
});

Write your express routes by using generator functions as middlewares.

const express = require('express-coroutine')(require('express'));
const app = express();
app.get('/user/:id', function* (req, res) {
  const user = yield User.findById(req.params.id);
  res.send(user);
})
app.get('/error', function* (req, res) {
  throw new Error('Bang!');
});
// also async function
app.get('/user2/:id', async function* (req, res) {
  const user = await User.findById(req.params.id);
  res.send(user);
});
app.listen(8000);

You can also define multiple generator functions just the express way.

const fn = function (req, res, next) {
  return new Promise((resolve, reject) => {
    if (req.params.user !== 'a') return reject(new Error('Bang!'));
    resolve('a');
  });
};
const middleware = function* (req, res, next) {
  yield fn(req, res, next);
};
const middleware2 = async function (req, res, next) {
  await fn(req, res, next);
  next();
};
app.get('/:user', middleware, function* (req, res) {
  res.send('it works!');
});
app.get('/:user', middleware2, async function (req, res) {
  res.send('it works!');
});

More detail demo can be found in test.js

Get coroutine

const coroutine = require('express-coroutine').coroutine;