Cake pattern example

fromScalaConsole.scala

case class User(username:String, password: String)

trait UserRepositoryComponent {
  val userRepository: UserRepository
  
  class UserRepository {
    def authenticate(user: User): User = { 
      println("authenticating user: " + user)
      user
     }
    def create(user: User) = println("creating user: " + user)
    def delete(user: User) = println("deleting user: " + user)
  }
}


trait UserServiceComponent { this: UserRepositoryComponent =>
  val userService: UserService
  class UserService {
    def authenticate(username: String, password: String): User = 
      userRepository.authenticate(User(username, password))  
  
    def create(username: String, password: String) = 
      userRepository.create(new User(username, password))
  
    def delete(user: User) = 
      userRepository.delete(user)
      
  }
}

object ComponentRegistry extends 
  UserServiceComponent with 
  UserRepositoryComponent 
{
  val userRepository = new UserRepository
  val userService = new UserService
}

/*

// In testing, I can provided some mocks for the components

object TestingComponentRegistry extends 
  UserServiceComponent with 
  UserRepositoryComponent 
{
  val userRepository = mock[UserRepository]
  val userService = mock[UserService]
}
*/