1 files changed, 9 insertions, 2 deletions
diff --git a/actionpack/lib/action_dispatch/routing/endpoint.rb b/actionpack/lib/action_dispatch/routing/endpoint.rb
index 88aa13c3e8..28bb20d688 100644
--- a/actionpack/lib/action_dispatch/routing/endpoint.rb
+++ b/actionpack/lib/action_dispatch/routing/endpoint.rb
@@ -1,10 +1,17 @@
+# frozen_string_literal: true
+
 module ActionDispatch
   module Routing
     class Endpoint # :nodoc:
       def dispatcher?;   false; end
       def redirect?;     false; end
-      def matches?(req); true;  end
-      def app;           self;  end
+      def matches?(req);  true; end
+      def app;            self; end
+      def rack_app;        app; end
+
+      def engine?
+        rack_app.is_a?(Class) && rack_app < Rails::Engine
+      end
     end
   end
 end