How to use sinon.js to fake the response of image

Question

How to use sinon.js to fake the response of image

I'm learning how to use sinon.js. I can fake normal AJAX but I need to request a image and I don't get xhr.response (it is undefined). How can I use sinon.js to fake the response of an image?

var url = 'http://www.google.com.hk/logos/2013/antoni_gauds_161st_birthday-1539005.2-  hp.jpg';
server.respondWith("GET", url, [200, {}, '']);
var xhr = new XMLHttpRequest();
xhr.open('GET', url, true);
xhr.responseType = 'arraybuffer';
xhr.addEventListener('load', function() {
//this.response is undefined
})
xhr.send(null);

How can I fake this image request?

javascript
node.js
unit-testing
sinon

Answer 1

I think an idea:

describe('...',function(){
    var xhr;
    before(function(){
       xhr = sinon.useFakeXMLHttpRequest();
       xhr.onCreate = function (x) {
      console.log(x)
       };
       //....
    }
    after(function(){
      xhr.restore();
    });
    it('....',function(){
       xhr.prototype.response = new ArrayBuffer(1024)
       // ... 
    });
}