public void AddServiceToBill_NoneExistsBillId_ThrowsArgumentOutOfRangeException() { clinic_service validService = new clinic_service(); int NoneExistsBillId = -1; Action act = () => _sut.AddServiceToBill(NoneExistsBillId, validService); act.Should().Throw <ArgumentOutOfRangeException>() .WithMessage("Bill Khong Ton Tai\nParameter name: billId"); }