xhr.responseXML is not implemented

[vcarel]

I'm using zombie to test an application downlading some XML files with XHR requests.
Unfortunatly, the xhr.responseXML method always returns null.

That's actually what is stated in the xhr.js file:

get responseXML() {
    // Not implemented yet
    return null;
}

It does not look straight forward to get a correct implementation of property (one would suggest to use jsdom's parseHtml). See driverdan/node-XMLHttpRequest#8

[vcarel]

I just found out that jsdom was using driverdan/node-XMLHttpRequest. But it looks like zombie is using it's own implementation...