title: how to test window.status variable
body: <p>I'm using wkhtmlpdf library to convert pdf from the HTML page. this page depends on heavy javascript functions (ajax calls, google maps) so that I had to use <code>--window-status</code> and <code>--javascript-delay</code> options. I'm setting the value <code>window.status="ready_to_print;"</code> when everything is done. It's working properly and pdf are rendering as It should be. </p>
  
  <p>Now I want to create a ruby on rails unit/integration test to check that the HTML page has rendered to the correct state. how can I test this using rpec, capybara or any other way?</p>