View difference between Paste ID: Syu6TLkm and rUF8gS35

 Good iPhone12 = new Good("IPhone 12");
 Good iPhone11 = new Good("IPhone 11");
 
 Warehouse warehouse = new Warehouse();
 
 Shop shop = new Shop(warehouse);
 
 warehouse.Delive(iPhone12, 10);
 warehouse.Delive(iPhone11, 1);
 
 //Вывод всех товаров на складе с их остатком
 
 Cart cart = shop.Cart();
 cart.Add(iPhone12, 4);
 cart.Add(iPhone11, 3); //при такой ситуации возникает ошибка так, как нет нужного количества товара на складе
 
 //Вывод всех товаров в корзине
 
 Console.WriteLine(cart.Order().Paylink);
 
 cart.Add(iPhone12, 9); //Ошибка, после заказа со склада убираются заказанные товары
 
 
 public class Warehouse : IDeliveryWarehouse
 {
     private readonly Dictionary<Good, int> _goods;
 
     public Warehouse()
     {
         GoodEqualityCompare goodEqualityCompare = new();
         _goods = new(goodEqualityCompare);
     }
 
     public void Delive(Good good, int countGoods)
     {
         good = good ?? throw new ArgumentNullException();
 
         if (countGoods < 0)
             throw new ArgumentOutOfRangeException();
 
-        if (_goods.ContainsKey(good))
+        if (_goods.ContainsKey(good) == false)
-            _goods[good] += countGoods;
+            _goods[good] = 0;
-        else
+
-            _goods.Add(good, countGoods);
+        _goods[good] += countGoods;
     }
 
     public bool CanIssue(Good good, int countGoods)
     {
         good = good ?? throw new ArgumentNullException();
 
         if (countGoods < 0)
             throw new ArgumentOutOfRangeException();
 
-        if (_goods.TryGetValue(good, out int count))
+        if (_goods.TryGetValue(good, out int count) == false)
-            return count >= countGoods;
+
-        else
+
         return count >= countGoods;
     }
 
     public void TransferForDelivery(Good good, int countGoods)
     {
         good = good ?? throw new ArgumentNullException();
 
         if (countGoods < 0)
             throw new ArgumentOutOfRangeException();
 
-        if (_goods.ContainsKey(good) && _goods[good] >= countGoods)
+        if (_goods.ContainsKey(good) == false || _goods[good] < countGoods)
-            _goods[good] -= countGoods;
+
-        else
+
         _goods[good] -= countGoods;
     }
 }
 
 public class Shop
 {
     private readonly Warehouse _warehouse;
 
     public Shop(Warehouse warehouse) => _warehouse = warehouse ?? throw new ArgumentNullException();
 
     public Cart Cart()
     {
         return new Cart(_warehouse);
     }
 }
 
 public class Cart
 {
     private readonly Dictionary<Good, int> _goods;
     private readonly IDeliveryWarehouse _warehouse;
 
     public Cart(IDeliveryWarehouse warehouse)
     {
         _warehouse = warehouse ?? throw new ArgumentNullException();
 
         GoodEqualityCompare goodEqualityCompare = new();
         _goods = new(goodEqualityCompare);
     }
 
     public void Add(Good good, int countGoods)
     {
         good = good ?? throw new ArgumentNullException();
 
         if (countGoods < 0)
             throw new ArgumentOutOfRangeException();
 
-        if (_goods.ContainsKey(good))
+        if (_warehouse.CanIssue(good, countGoods) == false)
-            _goods[good] += countGoods;
+            throw new InvalidOperationException();
-        else
+
-            _goods.Add(good, countGoods);
+        if (_goods.ContainsKey(good) == false)
             _goods[good] = 0;
 
         _goods[good] += countGoods;
     }
 
     public PayOrder Order()
     {
         foreach(var goods in _goods)
         {
             _warehouse.TransferForDelivery(goods.Key, goods.Value);
         }
 
         _goods.Clear();
         return new PayOrder();
     }
 }
 
 public class Good
 {
     public Good(string name)
     {
         if (string.IsNullOrEmpty(name))
             throw new ArgumentNullException();
 
         Name = name;
     }
 
     public string Name { get; }
 }
 
 public class PayOrder
 {
     public PayOrder() { }
 
     public string Paylink { get; }
 }
 
 public interface IDeliveryWarehouse
 {
     public bool CanIssue(Good good, int countGoods);
 
     public void TransferForDelivery(Good good, int countGoods);
 }
 
 public class GoodEqualityCompare : IEqualityComparer<Good>
 {
     public bool Equals(Good? good1, Good? good2)
     {
         if (ReferenceEquals(good1, good2))
             return true;
 
         if (good1 == null || good2 == null)
             return false;
 
         return good1.Name == good2.Name;
     }
 
     public int GetHashCode(Good good) => good.Name.GetHashCode();
 }