public async Task Test_AddCustomRule_ShouldThrowException()
{
const int maxSeats = 5;
var desiredSeats = CreateSeats().Where(s => s.Id <= (long)maxSeats).Select(Map).ToList();
PrepareReservationMocks(maxSeats, ScheduleA, ScheduleB, desiredSeats);
_reservationService.ClearRules(); // no rules active -> normally it would throw
_reservationService.AddRule(new SeatAvailableValidation()); // add seat available rule -> should throw now
Func <Task <ReservationDto> > addReservationAsync = async() => await _reservationService.AddReservationAsync(desiredSeats, ScheduleB.Id, 2L);
await addReservationAsync.Should().ThrowExactlyAsync <SeatValidationException>();
}