PositionalOperatorMongo.cs

    public class when_an_array_is_updated_internally : mongo_repository_context<CategoryModel>
    {
        static CategoryModel model = new CategoryModel { Name = "Test", FeatureTypes = new[] {
            new FeatureTypeModel{ Name = "feature1", DefaultValue = "Test1" },
            new FeatureTypeModel{ Name = "feature2", DefaultValue = "Test2" },
        }};

        Establish context = () => {
            InternalCollection.Save(model);
            cursor = InternalCollection.Find(Query.EQ("_id", "Test"));
        };
        Because of = () => _result = cursor.Collection.Update(
            new QueryDocument{{"FeatureTypes.Name", "feature2" }},
            Update.SetWrapped("FeatureTypes.$.DefaultValue", "Test3"));

        It should_not_return_an_error = () => _result.ErrorMessage.ShouldBeEmpty();
        It should_update_one_document = () => _result.DocumentsAffected.ShouldEqual(1);
        It should_updated_the_default_value_of_the_second_feature = () => 
            ((string)model.FeatureTypes[1].DefaultValue).ShouldEqual("Test3");

        static SafeModeResult _result;
        static MongoCursor<CategoryModel> cursor;
    }