Unit Testing NodeJS

Hi I am pretty new to NodeJs and I am trying to write my first tests.

I am kind of stuck with the setup, so I was hoping for some help.

I wrote these two functions:

app.js:

var express = require('express')
  , cors = require('cors')
  , app = express();

app.get('/a_nice_jsonp',cors(corsOptions), function(req, res, next){
  var result = parseCookies(req);
  res.jsonp(result);
});

app.get('',function(req,res,next){
  res.statusCode = 200;
  res.end()
});

I do not export it as module as it is my only file.

I assume it's pretty easy to write the tests for that. I started with something like this:

app-test.js:

var expect = require('expect.js');
var express = require('express');
var expressApp = express();

describe('app js test', function() {
  describe('GET /', function() {
    it('should respond to GET with empty path', function (req, res, body) {
      expressApp.get('', function(){
        expect(res.status).to.equal(200);
      });
    })
  });
});

app.js as well as app-test.js are currently in the same folder.

I suppose it really reads like a simple task, but I seem to fail over the setup of the test and how to do it.

Can anyone help me out here?