public async Task HandleAsync(ProductQuantityChanged @event)
{
var cartItemId = OrderItemReadModel.IdFor(@event.AggregateId.IdAsString(), @event.ProductId.IdAsString());
var cartItem = (await orderItemRepository
.FindAllAsync(x => x.Id == cartItemId))
.Single();
var cart = await orderRepository.GetByIdAsync(@event.AggregateId.IdAsString());
cart.TotalItems += @event.NewQuantity - @event.OldQuantity;
cartItem.Quantity = @event.NewQuantity;
await orderRepository.UpdateAsync(cart);
await orderItemRepository.UpdateAsync(cartItem);
}
