public void CashTest() { //arrange var customer1 = new Customer() { Name = "testuser1", CustomerID = 1 }; var customer2 = new Customer() { Name = "testuser2", CustomerID = 2 }; var seller = new Seller() { Name = "sellername", SellerID = 1 }; var product1 = new Product() { ProductID = 1, Name = "pr1", Price = 100, Count = 10 }; var product2 = new Product() { ProductID = 2, Name = "prod2", Price = 200, Count = 20 }; var cart1 = new Cart(customer1); cart1.Add(product1); cart1.Add(product1); cart1.Add(product2); var cart2 = new Cart(customer2); cart2.Add(product1); cart2.Add(product2); cart2.Add(product2); var cash = new Cash(1, seller); cash.Unqueue(cart1); cash.Unqueue(cart2); var cart1ExectedResult = 400; var cart2ExectedResult = 500; //act var cart1ActualResult = cash.Dequeue(); // var cart2ActualResult = cash.Dequeue(); //assert Assert.AreEqual(cart1ExectedResult, cart1ActualResult); // Assert.AreEqual(cart2ExectedResult, cart2ActualResult); // Assert.AreEqual(7, product1.Count); // Assert.AreEqual(17, product2.Count); }