public void CalculateIncome_YearIsNullAndDoNotInclude_Returns35() { // Arrange decimal target = 15 + 20; string firstId = "ScooterOne"; string secondId = "ScooterTwo"; decimal price = 0.5m; IList <RentedUnit> rentHistory = new List <RentedUnit> { new RentedUnit(1, firstId, DateTime.Now, price), new RentedUnit(2, secondId, DateTime.Now, price) }; // Act _calculations.ScooterService.AddScooter(firstId, price); _calculations.ScooterService.AddScooter(secondId, price); _calculations.ScooterService.GetScooterById(secondId).IsRented = true; rentHistory[0].StartTime = new DateTime(2021, 5, 12, 23, 30, 0); rentHistory[0].EndTime = new DateTime(2021, 5, 13, 1, 0, 0); rentHistory[0].TotalPrice = _calculations.CalculatePrice(rentHistory[0]); // Assert Assert.AreEqual(target, _calculations.CalculateIncome(null, false, rentHistory)); }