3 files changed, 34 insertions, 5 deletions
diff --git a/actionpack/lib/action_dispatch/routing/mapper.rb b/actionpack/lib/action_dispatch/routing/mapper.rb
index b52f66faf1..b1abbbe505 100644
--- a/actionpack/lib/action_dispatch/routing/mapper.rb
+++ b/actionpack/lib/action_dispatch/routing/mapper.rb
@@ -1613,8 +1613,8 @@ module ActionDispatch
         #   end
         #
         # Any routing helpers can be used inside a concern.
-        def concern(name, &block)
-          @concerns[name] = block
+        def concern(name, callable = nil, &block)
+          @concerns[name] = callable || block
         end
 
         # Use the named concerns
@@ -1631,7 +1631,7 @@ module ActionDispatch
         def concerns(*names)
           names.flatten.each do |name|
             if concern = @concerns[name]
-              instance_eval(&concern)
+              concern.call(self)
             else
               raise ArgumentError, "No concern named #{name} was found!"
             end
@@ -1645,6 +1645,10 @@ module ActionDispatch
         @concerns = {}
       end
 
+      def current_scope
+        @scope
+      end
+
       include Base
       include HttpHelpers
       include Redirection
diff --git a/actionpack/test/abstract_unit.rb b/actionpack/test/abstract_unit.rb
index e5054a9eb8..4f5b2895c9 100644
--- a/actionpack/test/abstract_unit.rb
+++ b/actionpack/test/abstract_unit.rb
@@ -358,6 +358,7 @@ end
 class ThreadsController  < ResourcesController; end
 class MessagesController < ResourcesController; end
 class CommentsController < ResourcesController; end
+class ReviewsController < ResourcesController; end
 class AuthorsController < ResourcesController; end
 class LogosController < ResourcesController; end
 
diff --git a/actionpack/test/dispatch/routing/concerns_test.rb b/actionpack/test/dispatch/routing/concerns_test.rb
index 21da3bd77a..8600da32ad 100644
--- a/actionpack/test/dispatch/routing/concerns_test.rb
+++ b/actionpack/test/dispatch/routing/concerns_test.rb
@@ -1,6 +1,16 @@
 require 'abstract_unit'
 
 class RoutingConcernsTest < ActionDispatch::IntegrationTest
+  class Reviewable
+    def self.call(mapper)
+      if mapper.current_scope[:controller] == 'posts'
+        mapper.resources :reviews
+      elsif mapper.current_scope[:controller] == 'videos'
+        mapper.resources :reviews, as: :video_reviews
+      end
+    end
+  end
+
   Routes = ActionDispatch::Routing::RouteSet.new.tap do |app|
     app.draw do
       concern :commentable do
@@ -11,8 +21,10 @@ class RoutingConcernsTest < ActionDispatch::IntegrationTest
         resources :images, only: :index
       end
 
-      resources :posts, concerns: [:commentable, :image_attachable] do
-        resource :video, concerns: :commentable
+      concern :reviewable, Reviewable
+
+      resources :posts, concerns: [:commentable, :image_attachable, :reviewable] do
+        resource :video, concerns: [:commentable, :reviewable]
       end
 
       resource :picture, concerns: :commentable do
@@ -63,6 +75,18 @@ class RoutingConcernsTest < ActionDispatch::IntegrationTest
     assert_equal "404", @response.code
   end
 
+  def test_accessing_callable_concern_from_resources
+    get "/posts/1/reviews/1"
+    assert_equal "200", @response.code
+    assert_equal "/posts/1/reviews/1", post_review_path(post_id: 1, id: 1)
+  end
+
+  def test_callable_concern_can_adapt_to_mapper
+    get "/posts/1/video/reviews/1"
+    assert_equal "200", @response.code
+    assert_equal "/posts/1/video/reviews/1", post_video_video_review_path(post_id: 1, id: 1)
+  end
+
   def test_accessing_concern_from_a_scope
     get "/videos/comments"
     assert_equal "200", @response.code