Attempting to use zombie in node.js to load content into a dynamically created iframe. Doesn't seem to work. I am new to node.js — what am I doing wrong?

ahh_zombie.js

browser = require('zombie');
browser = new browser();
browser.visit('https://dl.dropboxusercontent.com/u/625330/iframe/index.html')
document = browser.document;
iframe = document.createElement('iframe');
document.body.appendChild(iframe)
iframe.onload = function () {
  console.log('loaded') // this does not happen
};
iframe.src = 'https://dl.dropboxusercontent.com/u/625330/iframe/frame.html';

// Trying the above commands in node I get:
// iframe.location.href --> 'https://dl.dropboxusercontent.com/u/625330/iframe/frame.html'
// iframe.contentDocument.readyState --> 'loading'
// iframe.contentDocument.body --> null
// Seems like it never loads

//I put some console.log calls in the compiled zombie code (in dom_iframe.js):

HTML.HTMLFrameElement.prototype._attrModified = function(name, value, oldValue) {
  var onload, url,
    _this = this;

  HTML.HTMLElement.prototype._attrModified.call(this, name, value, oldValue);
  if (name === "name") {
    return this.ownerDocument.parentWindow.__defineGetter__(value, function() {
      return _this.contentWindow;
    });
  } else if (name === "src" && value) {
    console.log('HEY THERE') // I see this
    url = HTML.resourceLoader.resolve(this.ownerDocument, value);
    this.contentWindow.location = url;
    onload = function() {
      console.log('I AM LOADED') // I never see this
      _this.contentWindow.removeEventListener("load", onload);
      onload = _this.ownerDocument.createEvent("HTMLEvents");
      onload.initEvent("load", true, false);
      return _this.dispatchEvent(onload);
    };
    return this.contentWindow.addEventListener("load", onload);
  }
};

I also tried the equivalent just using jsdom and got similar results, so I don't think this is specific to zombie.

Here's a better self-contained script:

browser = require('zombie');
browser = new browser();
browser.visit('https://dl.dropboxusercontent.com/u/625330/iframe/index.html', function () {
    console.log('page loaded, waiting for iframe to load...')
    waiting = true;
    document = browser.document;
    iframe = document.createElement('iframe');
    document.body.appendChild(iframe)
    iframe.onload = function () {
        console.log('iframe loaded!')
        waiting = false;
    };
    iframe.src = 'https://dl.dropboxusercontent.com/u/625330/iframe/iframe.html';
    while(waiting) {
        // waiting forever...
    }
})

If I set browser.debug to true, I get this output:

Zombie: Opened window https://dl.dropboxusercontent.com/u/625330/iframe/index.html 
Zombie: GET https://dl.dropboxusercontent.com/u/625330/iframe/index.html => 200
Zombie: Loaded document https://dl.dropboxusercontent.com/u/625330/iframe/index.html
Zombie: Event loop is empty
page loaded, waiting for iframe to load...
Zombie: Opened window about:blank 
Zombie: Loaded document about:blank
Zombie: Opened window https://dl.dropboxusercontent.com/u/625330/iframe/iframe.html

But then it just hangs. Is the "Event loop is empty" message indicating a problem? I see that although I get "Opened window" with the iframe src, there is no GET request, so it seems like it is never trying to load the resource.

Oh dear, I've been working too much. Of course the while loop is blocking everything. Also the iframe content page is "frame.html" not "iframe.html". Alright, so now if I do:

browser = require('zombie');
browser = new browser();
browser.debug = true;
browser.visit('https://dl.dropboxusercontent.com/u/625330/iframe/index.html', function () {
    console.log('page loaded, waiting for iframe to load...')
    document = browser.document;
    iframe = document.createElement('iframe');
    iframe.onload = function () {
        console.log('iframe loaded!')
    };
    iframe.src = 'https://dl.dropboxusercontent.com/u/625330/iframe/frame.html';
    document.body.appendChild(iframe)
})

I get:

Zombie: Opened window https://dl.dropboxusercontent.com/u/625330/iframe/index.html 
Zombie: GET https://dl.dropboxusercontent.com/u/625330/iframe/index.html => 200
Zombie: Loaded document https://dl.dropboxusercontent.com/u/625330/iframe/index.html
Zombie: Event loop is empty
page loaded, waiting for iframe to load...
Zombie: Opened window about:blank 
Zombie: Loaded document about:blank
Zombie: Opened window https://dl.dropboxusercontent.com/u/625330/iframe/frame.html 
Zombie: GET https://dl.dropboxusercontent.com/u/625330/iframe/frame.html => 200

But the onload doesn't fire. Using addEventListener('load'... also doesn't work.