test.xchange.js

/**
 * Todo: have no idea if this is the best way to organize this, please pm for
 * suggestions
 */
var xchange = require('../xchange.js')
	,assert = require("assert")
	,chai = require('chai')
	,sinon = require('sinon')
	,expect = chai.expect;

describe('xchange library', function() {
	it('should have a bistamp object', function() {
		assert.equal(typeof xchange.bitstamp, 'object');
	});
});

describe('bitstamp object', function() {

	var bitstamp = xchange.bitstamp;

	before(function(done) {
		sinon.stub(request).yields(null, null, JSON.stringify({       //error here , request is not defined.  Although, it will work if I use xchange.request, but then breaks in the test below
			name : 'justin'
		}));
		done();
	});

	it('should have a getTicker function', function() {
		assert.equal(typeof bitstamp.getTicker, 'function');
	});

	it('getTicker function should call bitstamp ticker', function(done) {
		bitstamp.getTicker(function(error, result){
			request.get.called.should.be.equal(true);    //error request not defined.  even if i use xchange.request
			done();
		});
	});
});

xchange.js

'use strict';

var request = require('request');

function Bitstamp() {
};


Bitstamp.prototype.getTicker = function(callback) {
	request('https://www.bitstamp.net/api/ticker/', function(error, response, body) {
		if (error) {
			callback(error);
		} else {
			callback(null, response, body);
		}
	});
};

exports.bitstamp = new Bitstamp();