public void GenerateReceiptLine_ShouldFormatReceiptLineCorrectly(int quantity, string productName, decimal shelfPrice, string expectedResult)
{
// Arrange
var product = new Product();
var cartItem = new CartItem(product)
{
Quantity = quantity, ShelfPrice = shelfPrice
};
cartItem.Product.ProductName = productName;
// Act
string actualResult = cartItem.GenerateReceiptLine();
// Assert
Assert.Equal(expectedResult, actualResult);
}