public void OneUserStatisticTestZeroValues() { DateTime startDate = new DateTime(1991, 10, 11); DateTime endDate = new DateTime(1995, 11, 11); int idUser = 1; ReportsService reports = new ReportsService(); var userStatistic = reports.GetUserPaymentStatistic(startDate, endDate, 1); decimal paymentSum = userStatistic .Payments .Sum(t => t.PaySize); Assert.AreEqual(0, paymentSum); }