build_request_uri

# File actionpack/lib/action_controller/test_case.rb, line 486
      def build_request_uri(action, parameters)
        unless @request.env["PATH_INFO"]
          options = @controller.respond_to?(:url_options) ? @controller.__send__(:url_options).merge(parameters) : parameters
          options.update(
            :only_path => true,
            :action => action,
            :relative_url_root => nil,
            :_path_segments => @request.symbolized_path_parameters)

          url, query_string = @routes.url_for(options).split("?", 2)

          @request.env["SCRIPT_NAME"] = @controller.config.relative_url_root
          @request.env["PATH_INFO"] = url
          @request.env["QUERY_STRING"] = query_string || ""
        end
      end