# File lib/action_controller/assertions/response_assertions.rb, line 138
      def assert_template(expected = nil, message=nil)
        clean_backtrace do
          rendered = expected ? @response.rendered_file(!expected.include?('/')) : @response.rendered_file
          msg = build_message(message, "expecting <?> but rendering with <?>", expected, rendered)
          assert_block(msg) do
            if expected.nil?
              !@response.rendered_with_file?
            else
              expected == rendered
            end
          end
        end
      end