Merge pull request #700 from arenoir/sparse_fieldsets

sparse fieldsets

test/serializers/attributes_test.rb

@@ -12,7 +12,11 @@ module ActiveModel
         assert_equal([:name, :description],
                      @profile_serializer.class._attributes)
       end
+
+      def test_attributes_with_fields_option
+        assert_equal({name: 'Name 1'},
+                     @profile_serializer.attributes( { fields: [:name] } ) )
+      end
     end
   end
 end
-

test/serializers/fieldset_test.rb

@@ -0,0 +1,26 @@
+require 'test_helper'
+
+module ActiveModel
+  class Serializer
+    class FieldsetTest < Minitest::Test
+
+      def test_fieldset_with_hash
+        fieldset = ActiveModel::Serializer::Fieldset.new({'post' => ['id', 'title'], 'coment' => ['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
+        )
+      end
+    end
+  end
+end