How to unit test a NodeJs REST API server built using Express + Mongoose?

I use Jenkins (continuous integration server) and Mocha to test my app, and I found myself having the same problem as you. I configured Jenkins so it would execute this shell command:

npm installNODE_ENV=testing node app.js &npm mochapkill node

This runs the server for executing the tests, and then kills it. This also sets the NODE_ENV environment variable so I can run the server on a different port when testing, since Jenkins already uses port 8080.

Here is the code:

app.js:

...var port = 8080if(process.env.NODE_ENV === "testing")    port = 3000;...

test.js:

var request = require('request'),    assert = require('assert');    describe('Blabla', function() {      describe('GET /', function() {        it("should respond with status 200", function(done) {          request('http://127.0.0.1:3000/', function(err,resp,body) {            assert.equal(resp.statusCode, 200);            done();           });         });       });    });

I found exactly what I was looking for: testrest. I don't like its .txt file based syntax - I adapted to use a .json file instead for my specs.

I'd recommend giving Buster.JS a try. You can do Asynchronous tests, mocks/stubs, and fire up a server.