Use .find here as it is simpler and faster.

actionpack/lib/action_dispatch/routing/mapper.rb

@@ -1130,7 +1130,7 @@ def name_for_action(as, action)
             end
 
             candidate = name.select(&:present?).join("_").presence
-            candidate unless as.nil? && @set.routes.map(&:name).include?(candidate)
+            candidate unless as.nil? && @set.routes.find { |r| r.name == candidate }
           end
       end