Question 12
Consider designing an online gift store that delivers various gift items in a variety of ways, such as direct pick-up from the store, delivery by its own logistics team, or delivery by other delivery partners. To support the delivery process, an interface DeliveryProcessing is being designed, which is further implemented by the classes that provide the implementation for specific delivery processes. The interface DeliveryProcessing specifies the methods to be implemented by any delivery class, and those are packageOrder(), notifyCustomer(), bookDeliveryPartner() and deliver(). The online gift store also has digital gift items like gift coupons, software games, etc., and for delivering these items, most of the methods in the interface DeliveryProcessing are not relevant. However, since the interface DeliveryProcessing needs to be implemented by any delivery class, delivery classes for digital gift items also need to implement the methods from DeliveryProcessing which are not at all relevant to those items.
Identify the SOLID principle that is missing from the design process.
Single responsibility principle
Open-close principle
Liskov substitution principle
Interface segregation principle