passportjs, mocha, supertest ECONNREFUSED

I am trying to test authentication with mocha, supertest, and passport but I am getting connection refused error. I assume it has to do with the way I am starting my app...

var testUser = {
    "email": "test@test.com",
    "password": "test"
};

var app = require('../../server');

var request = require('superagent');
var user = request.agent(app);

describe('authentication api ', function() {

    it('should login a user', function(done) {
        user.post('/login')
            .send(testUser)
            .end(function(err, res) {
                if(err) throw err;
                done();
            });
    });
});

This user does exist in my mongo database. Within my server file which is two levels higher:

module.exports = app.listen(port, function() {
    console.log('app listening on port: ' + port);
});