gistfile1.rb

  def assert_layout(expected=nil, message=nil) 
     clean_backtrace do 
       layout = @response.layout ? @response.layout.split('/').last : false 
       msg = build_message(message, "expecting <?> but rendering with <?>", expected, layout) 
       assert_block(msg) do 
         if expected.nil? 
           @response.layout 
         else 
           expected == layout 
         end 
       end 
     end 
   end