gistfile1.js

// APP

var http = require('http');
    
module.exports = App = function() {}

App.prototype.init = function(options) {
  // handle options
  this.server = http.createServer(...)
}



// TEST
var http = require('http'),
    App = require('./app');

describe('App', function() {
  var app;
  
  beforeEach(function() {
    app = new App();
  })

  describe('.init', function() {
    it('should create http server', function() {
      spyOn(http, 'createServer');

      app.init({port: 3000});

      expect(http.createServer).toHaveBeenCalledWith(...)
    })
  });
});