public async Task GetFreeTermsByCarIdAsync_IdAndDatesPassed_Returns() { //Arrange int id = 1; var reservations = new List <Reservation>() { new Reservation() { RentalDate = DateTime.Now.AddDays(2), ReturnDate = DateTime.Now.AddDays(6) }, new Reservation() { RentalDate = DateTime.Now.AddDays(8), ReturnDate = DateTime.Now.AddDays(13) } }; var dates = new List <string>() { DateTime.Now.Date.ToString("dd/MM/yyyy"), DateTime.Now.AddDays(1).Date.ToString("dd/MM/yyyy"), DateTime.Now.AddDays(7).Date.ToString("dd/MM/yyyy"), DateTime.Now.AddDays(14).Date.ToString("dd/MM/yyyy") }; mockReservationRepository .Setup(p => p.FindAllByCarIdAsync(id)) .ReturnsAsync(reservations); var service = new TermService(mockReservationRepository.Object); //Act var returnedDates = await service.GetFreeTermsByCarIdAsync(id, DateTime.Now.AddDays(6), DateTime.Now.AddDays(13)); //Assert Assert.Equal(dates, returnedDates); }