Exemplo de teste usando specs2 e arquitetura limpa

SaveNewFriendsUsecaseSpec.scala

/**
 * https://blog.8thlight.com/uncle-bob/2012/08/13/the-clean-architecture.html
 * https://vimeo.com/43612849
 * https://etorreborre.github.io/specs2/guide/SPECS2-3.7/org.specs2.guide.Matchers.html
 * 
**/
package com.opportunity.objectives.usecases.user

import com.opportunity.objectives.exceptions.UserInvalidException
import com.opportunity.objectives.model.{Friend, User}
import com.opportunity.objectives.persistence.adapter.user.NewUserPersistenceAdapterMock
import org.specs2.mutable.Specification

class SaveNewFriendsUsecaseSpec extends Specification {
  "The save new friends usecase" should {
    args(sequential=true)
    "Save all new friends" ! usecaseForTest().saveAllNewFriends()
    "Try save friends with invalid user" ! usecaseForTest().trySaveFriendsWithInvalidUser()
  }

  case class usecaseForTest() {
    def saveAllNewFriends() = {
      val persistenceMock = new NewUserPersistenceAdapterMock()
      val usecase = new SaveNewFriendsUsecase(persistenceMock)

      val user = User(Map[String,Object]())
      val friends = List[Friend]()

      val savedUser = usecase.save(user, friends)

      val savedFriends = persistenceMock.findAllFriendsOf(savedUser)

      savedFriends.size must be equalTo 1
    }

    def trySaveFriendsWithInvalidUser() = {
      val persistenceMock = new NewUserPersistenceAdapterMock()
      val usecase = new SaveNewFriendsUsecase(persistenceMock)

      val user = User(Map[String,Object]())
      val friends = List[Friend]()

      usecase.save(user, friends) must throwA[UserInvalidException]
    }
  }
}