@patrickgod Bug in StoreCartItems Method in the Server's CartService.cs

[abouchrit]

Issue:

Assume that a user, let us call it USER_A, has a product P with a quantity x in its stored shoping cart.
Immagine that USER_A logged out from the session and went to the cart page. The current shopping list will be empty as expected.
Now, the user decided to add another product P with quantity z then he rememberd to log in. The current implementation will override the quantity of product P to z quantity.

Suggestion:

I belive that the quantity of product P should be the sum of (z+x). To achive that I implemented the StoredCartItems as below.
Code:

public async Task<ServiceResponse<List<CartProductResponse>>> StoreCartItems(List<CartItem> cartItems)
{
	cartItems.ForEach(cartItem => cartItem.UserId = GetUserId());
	// Get Stored Cart Items for the User
	var cartItemsFromDB = await _context.CartItems
		.Where(ci => ci.UserId == GetUserId())
		.ToListAsync();

	// If the locally stored cartItem is equal to the DB stored items then update quantity
	// otherwise add the cartItem to the DB
	foreach (var cartItem in cartItems)
	{
		var sameItem = cartItemsFromDB.Find(dbItem => dbItem.ProductId == cartItem.ProductId
		&& dbItem.ProductTypeId == cartItem.ProductTypeId);
		if (sameItem != null){
			sameItem.Quantity += cartItem.Quantity;
			// Update Existing item quantity
			_context.CartItems.Update(sameItem);
		}
		else
		{
			// Add the new item to the DB
			_context.CartItems.Add(cartItem);
		}
	}

	await _context.SaveChangesAsync();
	return await GetDbCartProducts();
}