Aws-lambda-http-router NPM

aws-lambda-http-router

Promise based router to facilitate unit testing of lambda handler

How-to from lambda handler

'use strict';
/*********************************************************************************
Dependencies
**********************************************************************************/
const promise             = require('bluebird')
/*********************************************************************************/

/*********************************************************************************/
//Handlers
/*********************************************************************************/
const echoHandler = (event, context, callback) => {
  const response = {
    statusCode: 200,
      body: {
        message: 'It is alive!'
      }
  };
  callback(null, response);
  return promise.resolve(response);
}

/*********************************************************************************/
//Sample Routes
/*********************************************************************************/
const routes = [
  {
    method: 'GET',
    path: '/',
    handler: echoHandler
  },
  {
    method: 'GET',
    path: '/echo',
    handler: echoHandler
  }
];

const httpRouter = require('aws-lambda-http-router').create(routes);
/*********************************************************************************/

exports.handler = httpRouter.handler;

How-to from Mocha Tests

//Handler to process the request
const echoHandler = (event, context, callback) => {
  const response = {
    statusCode: 200,
    body: 'I am alive'
  }
  callback(null, response);
  return Promise.resolve(response);
}
      
//Definitions of routes
const routes = [
  {
    method: 'GET',
    path: '/',
    handler: echoHandler
  },
  {
    method: 'POST',
    path: '/',
    handler: echoHandler
  }
];
      
//Initiate router with routes
const httpRouter		    = require('aws-lambda-http-router').create(routes);

//Emulated event as passed from API-Gateway to Lambda function
const echoEvent = {
  resource: "/",
  path: "/",
  httpMethod: "GET",
  headers: {
    Accept: "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8",
    "Accept-Encoding": "gzip, deflate, br",
    "Accept-Language": "en-US,en;q=0.8",
    "Cache-Control": "max-age=0",
    "CloudFront-Forwarded-Proto": "https",
    "CloudFront-Is-Desktop-Viewer": "true",
    "CloudFront-Is-Mobile-Viewer": "false",
    "CloudFront-Is-SmartTV-Viewer": "false",
    "CloudFront-Is-Tablet-Viewer": "false",
    "CloudFront-Viewer-Country": "BS",
    DNT: "1",
    Host: "oqrzdhckn8.execute-api.us-east-2.amazonaws.com",
    "Upgrade-Insecure-Requests": "1",
    "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36",
    "Via": "1.1 85da55ad6484d43ed71e004ad6f0496f.cloudfront.net (CloudFront)",
    "X-Amz-Cf-Id": "vUWr64h90lzJf8sRDnYC7oIJC3MJEYNy9HPxW1X1UtgTaICkcGNuig==",
    "X-Amzn-Trace-Id": "Root=1-5970c7dd-1ebf6ec97c53a8f8519b39a1",
    "X-Forwarded-For": "108.60.230.202, 54.239.140.75",
    "X-Forwarded-Port": "443",
    "X-Forwarded-Proto": "https"
  },
  queryStringParameters: null,
  pathParameters: null,
  stageVariables: null,
  requestContext: {
    path: "/poc/",
    accountId: "811322200214",
    resourceId: "ag8lo7kr1e",
    stage: "poc",
    requestId: "8c44458a-6d5d-11e7-998a-e98ca284c3df",
    identity: {
      cognitoIdentityPoolId: null,
      accountId: null,
      cognitoIdentityId: null,
      caller: null,
      apiKey: "",
      sourceIp: "108.60.230.202",
      accessKey: null,
      cognitoAuthenticationType: null,
      cognitoAuthenticationProvider: null,
      userArn: null,
      userAgent: "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36",
      user: null
    },
    resourcePath: "/",
    httpMethod: "GET",
    apiId: "oqrzdhckn8"
  },
  body: null,
  isBase64Encoded: false
};

//Emulated callback as passed from API-Gateway to Lambda function
const lambdaCallback = (err, result) => {
  console.log('Lambda Callback(err, result):');
  console.log('result: ', result);
  console.error('err: ', err);
};

//Emulated context as passed from API-Gateway to Lambda function
const lambdaContext = {
  succeed: (data) => {
    console.log(data);
  },
  fail: (err) => {
    console.error(err);
  }
};

//Mocha test
describe('http-router', function() {
	describe('#GET: /', function() {
		it('Should return statusCode 200', function(done) {
      httpRouter.handler(echoEvent, lambdaContext, lambdaCallback)
        .then(response => {
          assert.equal(response.statusCode, 200, 'Status code should be equal 200');
          done();
        });
		});
  });
});