push functional test specific methods to it's own module

actionpack/lib/action_controller/metal/testing.rb

@@ -4,20 +4,22 @@ module Testing
 
     include RackDelegation
 
-    def set_response!(request)
-      super unless @_response
-    end
-
-    def recycle!
-      @_url_options = nil
-    end
-
     # TODO : Rewrite tests using controller.headers= to use Rack env
     def headers=(new_headers)
       @_response ||= ActionDispatch::Response.new
       @_response.headers.replace(new_headers)
     end
 
+    # Behavior specific to functional tests
+    module Functional # :nodoc:
+      def set_response!(request)
+      end
+
+      def recycle!
+        @_url_options = nil
+      end
+    end
+
     module ClassMethods
       def before_filters
         _process_action_callbacks.find_all{|x| x.kind == :before}.map{|x| x.name}

actionpack/lib/action_controller/test_case.rb

@@ -491,7 +491,11 @@ def process(action, http_method = 'GET', *args)
         @controller.response = @response
 
         build_request_uri(action, parameters)
-        @controller.class.class_eval { include Testing }
+
+        unless @controller.respond_to?(:recycle!)
+          @controller.extend(Testing::Functional)
+          @controller.class.class_eval { include Testing }
+        end
 
         @controller.recycle!
         name = @request.parameters[:action]