Help designing a order manager class
问题 So I have an order manager class that looks like: public class OrderManager { private IDBFactory _dbFactory; private Order _order; public OrderManager(IDBFactory dbFactory) { _dbFactory = dbFactory; } public void Calculate() { _order.SubTotal _order.ShippingTotal _order.TaxTotal _order.GrandTotal } } Now, the point here is to have a flexible/testible design. I am very concerned about being able to write solid unit tests around this Calculate method. Considerations: 1. Shipping has to be