code: def js(code)
        XhrProxy.context = self
        @__page ||= Harmony::Page.new(XHR_MOCK_SCRIPT + rewrite_script_paths(@response.body.to_s))
        Harmony::Page::Window::BASE_RUNTIME.wait
        @__page.execute_js(code)
      end
docs: Execute javascript within the context of a view.
  
   @example
  
       class PeopleControllerTest < ActionController::TestCase
         get :index
         assert_equal 'People: index', js('document.title')
       end
  
   @param [String]
     code javascript code to evaluate
  
   @return [Object]
     value of last javascript statement, cast to an equivalent ruby object
  
   @raise [Johnson::Error]
     javascript code exception