Merge pull request #30836 from shioyama/generated_attribute_methods_include_mutex

Include Mutex_m into GeneratedAttributeMethods instead of extending instance

activerecord/lib/active_record/attribute_methods.rb

@@ -33,7 +33,9 @@ def self.set_name_cache(name, value)
 
     BLACKLISTED_CLASS_METHODS = %w(private public protected allocate new name parent superclass)
 
-    class GeneratedAttributeMethods < Module; end # :nodoc:
+    class GeneratedAttributeMethods < Module #:nodoc:
+      include Mutex_m
+    end
 
     module ClassMethods
       def inherited(child_class) #:nodoc:
@@ -42,7 +44,7 @@ def inherited(child_class) #:nodoc:
       end
 
       def initialize_generated_modules # :nodoc:
-        @generated_attribute_methods = GeneratedAttributeMethods.new { extend Mutex_m }
+        @generated_attribute_methods = GeneratedAttributeMethods.new
         @attribute_methods_generated = false
         include @generated_attribute_methods
 

activerecord/test/cases/attribute_methods_test.rb

@@ -999,6 +999,11 @@ def some_method_that_is_not_on_super
     assert_equal ["title"], model.accessed_fields
   end
 
+  test "generated attribute methods ancestors have correct class" do
+    mod = Topic.send(:generated_attribute_methods)
+    assert_match %r(GeneratedAttributeMethods), mod.inspect
+  end
+
   private
 
     def new_topic_like_ar_class(&block)