    # 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