public void Check_That_DateFilter_Returns_Right_Delegate_By_LastMonth() { // Arrange var container = new GameFilterContainer { Model = new GamesFilterModel { DatePeriod = DatePeriod.LastMonth, } }; var filter = new DateFilter(); IEnumerable <Game> list = GetGamesList(); // Act filter.Execute(container); Func <Game, bool> resultCondition = CombinePredicate <Game> .CombineWithAnd(container.Conditions); IEnumerable <Game> result = list.Where(x => (resultCondition(x))); // Assert Assert.IsTrue(result.Count() == 2); }