public Either <Cart, Error> Add_(Guid productId, int quantity, TemporaryReservation temporaryReservation)
{
// NB: for sure we could check that before, but in real, we should test current cart nb + quantity added here...
if (quantity > 99)
{
return(Either <Cart, Error> .Right(new Error("Too many of the same product in cart")));
}
// modify this
// OR probably a new cart instance instead of modifying this...
return(Either <Cart, Error> .Left(this));
}
// bool return type is only relevant with CartControllerIfs implementation
public bool Add(Guid productId, int quantity, TemporaryReservation temporaryReservation)
{
throw new NotImplementedException();
}