2 files changed, 40 insertions, 27 deletions
diff --git a/actionpack/lib/action_dispatch/routing/mapper.rb b/actionpack/lib/action_dispatch/routing/mapper.rb
index 51bafb539f..1acfb2bfe8 100644
--- a/actionpack/lib/action_dispatch/routing/mapper.rb
+++ b/actionpack/lib/action_dispatch/routing/mapper.rb
@@ -283,12 +283,16 @@ module ActionDispatch
           end
 
           def app(blocks)
-            if to.respond_to?(:call)
-              Constraints.new(to, blocks, Constraints::CALL)
-            elsif blocks.any?
-              Constraints.new(dispatcher(defaults.key?(:controller)), blocks, Constraints::SERVE)
+            if to.is_a?(Class) && to < ActionController::Metal
+              Routing::RouteSet::StaticDispatcher.new to
             else
-              dispatcher(defaults.key?(:controller))
+              if to.respond_to?(:call)
+                Constraints.new(to, blocks, Constraints::CALL)
+              elsif blocks.any?
+                Constraints.new(dispatcher(defaults.key?(:controller)), blocks, Constraints::SERVE)
+              else
+                dispatcher(defaults.key?(:controller))
+              end
             end
           end
 
@@ -368,7 +372,7 @@ module ActionDispatch
           end
 
           def dispatcher(raise_on_name_error)
-            @set.dispatcher raise_on_name_error
+            Routing::RouteSet::Dispatcher.new raise_on_name_error
           end
       end
 
diff --git a/actionpack/lib/action_dispatch/routing/route_set.rb b/actionpack/lib/action_dispatch/routing/route_set.rb
index af6f0de556..e4b8d5993e 100644
--- a/actionpack/lib/action_dispatch/routing/route_set.rb
+++ b/actionpack/lib/action_dispatch/routing/route_set.rb
@@ -27,11 +27,10 @@ module ActionDispatch
         def dispatcher?; true; end
 
         def serve(req)
-          params = req.path_parameters
-          controller = controller_reference(req) do
-            return [404, {'X-Cascade' => 'pass'}, []]
-          end
-          dispatch(controller, params[:action], req)
+          params     = req.path_parameters
+          controller = controller req
+          res        = controller.make_response! req
+          dispatch(controller, params[:action], req, res)
         rescue NameError => e
           if @raise_on_name_error
             raise ActionController::RoutingError, e.message, e.backtrace
@@ -40,16 +39,26 @@ module ActionDispatch
           end
         end
 
-      protected
-        def controller_reference(req, &block)
-          req.controller_class(&block)
+      private
+
+        def controller(req)
+          req.controller_class
         end
 
-      private
+        def dispatch(controller, action, req, res)
+          controller.dispatch(action, req, res)
+        end
+      end
 
-        def dispatch(controller, action, req)
-          controller.action(action).call(req.env)
+      class StaticDispatcher < Dispatcher
+        def initialize(controller_class)
+          super(false)
+          @controller_class = controller_class
         end
+
+        private
+
+        def controller(_); @controller_class; end
       end
 
       # A NamedRouteCollection instance is a collection of named routes, and also
@@ -171,9 +180,9 @@ module ActionDispatch
             private
 
             def optimized_helper(args)
-              params = parameterize_args(args) { |k|
+              params = parameterize_args(args) do
                 raise_generation_error(args)
-              }
+              end
 
               @route.format params
             end
@@ -285,7 +294,7 @@ module ActionDispatch
 
       attr_accessor :formatter, :set, :named_routes, :default_scope, :router
       attr_accessor :disable_clear_and_finalize, :resources_path_names
-      attr_accessor :default_url_options, :dispatcher_class
+      attr_accessor :default_url_options
       attr_reader :env_key
 
       alias :routes :set
@@ -328,7 +337,6 @@ module ActionDispatch
         @set    = Journey::Routes.new
         @router = Journey::Router.new @set
         @formatter = Journey::Formatter.new self
-        @dispatcher_class = Routing::RouteSet::Dispatcher
       end
 
       def relative_url_root
@@ -343,6 +351,11 @@ module ActionDispatch
         ActionDispatch::Request
       end
 
+      def make_request(env)
+        request_class.new env
+      end
+      private :make_request
+
       def draw(&block)
         clear! unless @disable_clear_and_finalize
         eval_block(block)
@@ -386,10 +399,6 @@ module ActionDispatch
         @prepend.each { |blk| eval_block(blk) }
       end
 
-      def dispatcher(raise_on_name_error)
-        dispatcher_class.new(raise_on_name_error)
-      end
-
       module MountedHelpers
         extend ActiveSupport::Concern
         include UrlFor
@@ -700,7 +709,7 @@ module ActionDispatch
       end
 
       def call(env)
-        req = request_class.new(env)
+        req = make_request(env)
         req.path_info = Journey::Router::Utils.normalize_path(req.path_info)
         @router.serve(req)
       end
@@ -716,7 +725,7 @@ module ActionDispatch
           raise ActionController::RoutingError, e.message
         end
 
-        req = request_class.new(env)
+        req = make_request(env)
         @router.recognize(req) do |route, params|
           params.merge!(extras)
           params.each do |key, value|