助手方法可以放在服务中吗？

Question

I have a service that looks like:

 class UsersService { create() {...} update() {...} getRandomUsername() {...} isUserOld() {...} }

Should methods "getRandomUsername" and "isUserOld" be placed inside service? Or they should be moved to some separate "UsersHelper" class and be called from there?

Answer 1

Service layer ind DDD (Domain Driven Design) architecture is supposed to be responsible for domain operations AND Business Logic. If you consider operations "getRandomUsername" and "isUserOld" Business Logic then it's fine to have them in the UserService service. Especially if they really do operations on/with the "User" entity.

Usually people try to avoid creating classes like Helpers or Managers, because what happens is that eventually everyone in your team will be putting all the "general" code inside of one GodHelper class. If you want to create several helper classes for every entity in your domain then you basically recreate a service layer.