express-promise-router

A simple wrapper for Express 4's Router that allows middleware to return promises. This package makes it simpler to write route handlers for Express when dealing with promises by reducing duplicate code.

Getting Started

Install the module with: npm install express-promise-router --save.

express-promise-router is a drop-in replacement for Express 4's Router.

Documentation

Middleware and route handlers can simply return a promise. If the promise is rejected, express-promise-router will call next with the reason. This functionality removes the need to explicitly define a rejection handler.

// With Express 4's router
var router = require('express').Router();
 
router.use('/url', function (req, res, next) {
    Promise.reject().catch(next);
})
 
// With express-promise-router
var router = require('express-promise-router')();
 
router.use('/url', function (req, res) {
    return Promise.reject();
})

Calling next() and next('route') is supported by resolving a promise with either 'next' or 'route'. No action is taken if the promise is resolved with any other value.

router.use('/url', function (req, res) {
    // equivalent to calling next()
    return Promise.resolve('next');
});
 
router.use('/url', function (req, res) {
    // equivalent to calling next('route')
    return Promise.resolve('route');
});

This package still allows calling next directly.

router = require('express-promise-router')();
 
// still works as expected
router.use('/url', function (req, res, next) {
    next();
});

Contributing

Add unit tests for any new or changed functionality. Lint and test your code using npm test.

Unit tests use mocha and chai.

We use eslint, but styling is controlled mostly by prettier which reformats your code before you commit. You can manually trigger a reformat using npm run-script format.

Release History

v3.0.3

• Improve package dependencies #57

v3.0.2

• Add default property to simulate es6 style default export #50 #51

v3.0.1

• Remove @types/express peerDependency #47 #48

v3.0.0

• Update to chai 4
• Update to mocha 4
• Update to eslint 4
• Update to sinon 4
• Reduced lodash usage and footprint #41
• Added TypeScript definitions #47

v2.0.0

• Dropped support for old Node versions (<4).
  • Supported: Node 4 LTS, Node 6 LTS, Node current.
• Use native promises instead of bluebird. (One less dependency!)
• Use is-promise module instead of our own function.

v1.1.1

• Update to lodash 4
• Update to bluebird 3

v1.1.0

• Improvements to error reporting
• Support for route array
• Bug fixes

License

Copyright (c) 2014 Alex Whitney. Licensed under the MIT license.