Added test case for association propagating options

test/unit/active_model/serializer/options_test.rb

@@ -21,6 +21,9 @@ module ActiveModel
             serialization_options[:force_the_description]
           end
         end
+
+        @category = Category.new({name: 'Category 1'})
+        @category_serializer = CategorySerializer.new(@category)
       end
 
       def test_filtered_attributes_serialization
@@ -29,6 +32,11 @@ module ActiveModel
           'profile' => { name: 'Name 1', description: forced_description }
         }, @profile_serializer.as_json(force_the_description: forced_description))
       end
+
+      def test_filtered_attributes_serialization_across_association
+        assert_equal("'T1'",
+            @category_serializer.as_json(highlight_keyword: 'T1')['category'][:posts][0][:title])
+      end
     end
   end
 end