Refactor to remove controller class from route to request

This refactoring moves the controller class name that was on the route
set to the request. The purpose of this refactoring is for changes we
need to move controller tests to integration tests, mainly being able to
access the controller on the request instead of having to go through
the router.

[Eileen M. Uchitelle & Aaron Patterson]

3 files changed, 21 insertions, 41 deletions

diff --git a/actionpack/lib/action_dispatch/http/request.rb b/actionpack/lib/action_dispatch/http/request.rb
index 1f480eec73..1189111f20 100644
--- a/actionpack/lib/action_dispatch/http/request.rb
+++ b/actionpack/lib/action_dispatch/http/request.rb
@@ -67,6 +67,18 @@ module ActionDispatch
       end
     end
 
+    def controller_class
+      check_path_parameters!
+      params = path_parameters
+      controller_param = params[:controller].underscore if params.key?(:controller)
+      params[:action] ||= 'index'
+
+      yield unless controller_param
+
+      const_name = "#{controller_param.camelize}Controller"
+      ActiveSupport::Dependencies.constantize(const_name)
+    end
+
     def key?(key)
       @env.key?(key)
     end
diff --git a/actionpack/lib/action_dispatch/routing/route_set.rb b/actionpack/lib/action_dispatch/routing/route_set.rb
index c298080ac8..35385a5d9b 100644
--- a/actionpack/lib/action_dispatch/routing/route_set.rb
+++ b/actionpack/lib/action_dispatch/routing/route_set.rb
@@ -27,41 +27,18 @@ module ActionDispatch
         def dispatcher?; true; end
 
         def serve(req)
-          req.check_path_parameters!
           params = req.path_parameters
-
-          prepare_params!(params)
-
-          controller = controller(params, @raise_on_name_error) do
+          controller = controller_reference(req) do
             return [404, {'X-Cascade' => 'pass'}, []]
           end
-
           dispatch(controller, params[:action], req)
-        end
-
-        def prepare_params!(params)
-          normalize_controller!(params)
-          merge_default_action!(params)
-        end
-
-        # If this is a default_controller (i.e. a controller specified by the user)
-        # we should raise an error in case it's not found, because it usually means
-        # a user error. However, if the controller was retrieved through a dynamic
-        # segment, as in :controller(/:action), we should simply return nil and
-        # delegate the control back to Rack cascade. Besides, if this is not a default
-        # controller, it means we should respect the @scope[:module] parameter.
-        def controller(params, raise_on_name_error=true)
-          controller_reference params.fetch(:controller) { yield }
         rescue NameError => e
-          raise ActionController::RoutingError, e.message, e.backtrace if raise_on_name_error
-          yield
+          raise ActionController::RoutingError, e.message, e.backtrace if @raise_on_name_error
         end
 
       protected
-
-        def controller_reference(controller_param)
-          const_name = "#{controller_param.camelize}Controller"
-          ActiveSupport::Dependencies.constantize(const_name)
+        def controller_reference(req, &block)
+          req.controller_class(&block)
         end
 
       private
@@ -69,14 +46,6 @@ module ActionDispatch
         def dispatch(controller, action, req)
           controller.action(action).call(req.env)
         end
-
-        def normalize_controller!(params)
-          params[:controller] = params[:controller].underscore if params.key?(:controller)
-        end
-
-        def merge_default_action!(params)
-          params[:action] ||= 'index'
-        end
       end
 
       # A NamedRouteCollection instance is a collection of named routes, and also
@@ -756,14 +725,13 @@ module ActionDispatch
           req.path_parameters = old_params.merge params
           app = route.app
           if app.matches?(req) && app.dispatcher?
-            dispatcher = app.app
-
-            dispatcher.controller(params, false) do
+            begin
+              req.controller_class
+            rescue NameError
               raise ActionController::RoutingError, "A route matches #{path.inspect}, but references missing controller: #{params[:controller].camelize}Controller"
             end
 
-            dispatcher.prepare_params!(params)
-            return params
+            return req.path_parameters
           end
         end
 
diff --git a/actionpack/test/abstract_unit.rb b/actionpack/test/abstract_unit.rb
index 60e2cea8a2..fa0b6087ba 100644
--- a/actionpack/test/abstract_unit.rb
+++ b/actionpack/test/abstract_unit.rb
@@ -122,7 +122,7 @@ class ActionDispatch::IntegrationTest < ActiveSupport::TestCase
   class StubDispatcher < ::ActionDispatch::Routing::RouteSet::Dispatcher
     protected
     def controller_reference(controller_param)
-      controller_param
+      controller_param.params[:controller]
     end
 
     def dispatch(controller, action, env)