Extract attributes filtering from serializer into adapter.

test/serializers/attributes_test.rb

@@ -18,11 +18,6 @@ module ActiveModel
           @profile_serializer.class._attributes)
       end
 
-      def test_attributes_with_fields_option
-        assert_equal({ name: 'Name 1' },
-          @profile_serializer.attributes(fields: [:name]))
-      end
-
       def test_attributes_inheritance_definition
         assert_equal([:id, :body], @serializer_klass._attributes)
       end

test/serializers/fieldset_test.rb

@@ -4,22 +4,11 @@ module ActiveModel
   class Serializer
     class FieldsetTest < Minitest::Test
       def test_fieldset_with_hash
-        fieldset = ActiveModel::Serializer::Fieldset.new({ 'post' => %w(id title), 'coment' => ['body'] })
+        fieldset = ActiveModel::Serializer::Fieldset.new('post' => %w(id title), 'comment' => ['body'])
+        expected = { :post => [:id, :title], :comment => [:body] }
 
-        assert_equal(
-          { :post => [:id, :title], :coment => [:body] },
-          fieldset.fields
-        )
-      end
-
-      def test_fieldset_with_array_of_fields_and_root_name
-        fieldset = ActiveModel::Serializer::Fieldset.new(['title'], 'post')
-
-        assert_equal(
-          { :post => [:title] },
-          fieldset.fields
-        )
+        assert_equal(expected, fieldset.fields)
       end
     end
   end
-end
+end