Merge pull request #23331 from amatsuda/valid_scope_name

Warn if a named scope is overwriting an existing scope or method

activerecord/lib/active_record/scoping/named.rb

@@ -151,6 +151,7 @@ def scope(name, body, &block)
               "a class method with the same name."
           end
 
+          valid_scope_name?(name)
           extension = Module.new(&block) if block
 
           if body.respond_to?(:to_proc)
@@ -169,6 +170,15 @@ def scope(name, body, &block)
             end
           end
         end
+
+      protected
+
+        def valid_scope_name?(name)
+          if respond_to?(name, true)
+            logger.warn "Creating scope :#{name}. " \
+                        "Overwriting existing method #{self.name}.#{name}."
+          end
+        end
       end
     end
   end

activerecord/test/cases/scoping/named_scoping_test.rb

@@ -440,6 +440,25 @@ def test_table_names_for_chaining_scopes_with_and_without_table_name_included
     end
   end
 
+  def test_scopes_with_reserved_names
+    class << Topic
+      def public_method; end
+      public :public_method
+
+      def protected_method; end
+      protected :protected_method
+
+      def private_method; end
+      private :private_method
+    end
+
+    [:public_method, :protected_method, :private_method].each do |reserved_method|
+      assert Topic.respond_to?(reserved_method, true)
+      ActiveRecord::Base.logger.expects(:warn)
+      silence_warnings { Topic.scope(reserved_method, -> { }) }
+    end
+  end
+
   def test_scopes_on_relations
     # Topic.replied
     approved_topics = Topic.all.approved.order('id DESC')