process

# File actionpack/lib/action_dispatch/testing/integration.rb, line 326
        def process(method, path, params: nil, headers: nil, env: nil, xhr: false, as: nil)
          request_encoder = RequestEncoder.encoder(as)

          if path =~ %{://}
            location = URI.parse(path)
            https! URI::HTTPS === location if location.scheme
            if url_host = location.host
              default = Rack::Request::DEFAULT_PORTS[location.scheme]
              url_host += ":#{location.port}" if default != location.port
              host! url_host
            end
            path = request_encoder.append_format_to location.path
            path = location.query ? "#{path}?#{location.query}" : path
          else
            path = request_encoder.append_format_to path
          end

          hostname, port = host.split(':')

          request_env = {
            :method => method,
            :params => request_encoder.encode_params(params),

            "SERVER_NAME"     => hostname,
            "SERVER_PORT"     => port || (https? ? "443" : "80"),
            "HTTPS"           => https? ? "on" : "off",
            "rack.url_scheme" => https? ? "https" : "http",

            "REQUEST_URI"    => path,
            "HTTP_HOST"      => host,
            "REMOTE_ADDR"    => remote_addr,
            "CONTENT_TYPE"   => request_encoder.content_type,
            "HTTP_ACCEPT"    => accept
          }

          if xhr
            headers ||= {}
            headers['HTTP_X_REQUESTED_WITH'] = 'XMLHttpRequest'
            headers['HTTP_ACCEPT'] ||= [Mime[:js], Mime[:html], Mime[:xml], 'text/xml', '*/*'].join(', ')
          end

          # this modifies the passed request_env directly
          if headers.present?
            Http::Headers.from_hash(request_env).merge!(headers)
          end
          if env.present?
            Http::Headers.from_hash(request_env).merge!(env)
          end

          session = Rack::Test::Session.new(_mock_session)

          # NOTE: rack-test v0.5 doesn't build a default uri correctly
          # Make sure requested path is always a full uri
          session.request(build_full_uri(path, request_env), request_env)

          @request_count += 1
          @request  = ActionDispatch::Request.new(session.last_request.env)
          response = _mock_session.last_response
          @response = ActionDispatch::TestResponse.from_response(response)
          @response.request = @request
          @response.response_parser = RequestEncoder.parser(@response.content_type)
          @html_document = nil
          @url_options = nil

          @controller = @request.controller_instance

          response.status
        end