lambda-router

A lightweight Express-like HTTP request router for AWS Lambda functions triggered by API Gateway's Lambda Proxy Integration.

This might be helpful if ...

• You use API Gateway's Lambda Proxy Integration.
• Your Lambda function will execute different logic based on the AWS event's httpMethod and path parameters.
• Your Lambda function will use the Node.js 8.10 runtime with new async-style handler.

If these conditions DO NOT apply to you then see the bottom of this README for some alternative routing solutions.

Key Features

• Route handlers are invoked with the AWS event and context objects rather than HTTP request/response
• Written for the new [Node.js 8.10 async-style handler]
• Uses the path-to-regexp module to support similar route matching as Express (e.g. '/:foo/:bar+')

Getting Started

npm install @funcmatic/lambda-router

// function.js
'use strict'

const app = require('@funcmatic/lambda-router')

// define a route 
app.get('/user/:id', async ({ event, context }, params) => {
  var ret = { 'user': params.userid }
  return ret
})  

// This will be invoked by AWS Lambda and 
exports.handler = async (event, context) => {
  // You can pass any data into your route 
  var ctx = { event, context }  
  return await app.dispatch(ctx)
}

How to Use

Route methods

Route paths

Route parameters

Route handlers

Response methods

Running the tests

Most existing Javascript routers require an HTTP request/response object. Here an example of route using Express:

// Router handler in Expresss is passed in a Node HTTP request and response object
app.get('/', function (req, res) {
  res.send('hello world')
})

You can define the equivalent route handler using lambda-router by:

// lambda-router uses similar syntax but passes in the AWS event and context 
// objects instead of request/response
app.get('/', async function ({event, context}) {
  
  return {
    statusCode: 200,
    headers: {
     "Content-Type": "text/plain"
    },
    body: 'hello world'
  }
})

Alternative Routing Solutions

Why?

Micro server-side URL router that can be used with AWS Lambda (NodeJS) and has Express-like routing syntax. Written in vanilla javascript that natively runs in Node v8.10 and does not depend on any other external packages or modules.

Inspired and adapted from visionmedia/page.js — a simple express-like client-side router.

Test code