[Scala] [Mokito]如何將Future函數存根以引發異常

Question

我正在編寫用於對存儲庫進行存根的測試用例， Future函數將引發Exception以模擬某些DB錯誤。

我期望Repository.create拋出數據庫異常，它將由Actor .recover{}處理。 但這會引發異常，並且無法被.recover捕獲

// test 
it should "return NOT created message if exception thrown" in {
    val repository = mock[Repository]
    val service = TestActorRef(props(repository))
    implicit val ec: ExecutionContext = service.dispatcher
    val mockTeam = mock[Team]

    when(repository.create(any[Team])(same(ec))).thenReturn(Future.failed(throw new Exception))
    service ! CreateTeam(mockTeam)
    expectMsg(TeamNotCreated())
}


// service == actor
override def receive = {
    case CreateTeam(team) => createTeam(team)
    .recover {
      case error: Exception => TeamNotCreated()
    }.pipeTo(sender())
}
private def createTeam(team: Team)
  : Future[TeamCreateEvent] = {
        for {
          newTeam <- repository.create(team = team)
        } yield {
          if (newTeam isDefined) TeamCreated(newTeam)
          else TeamNotCreated()
        }
      }

// repository
override def create(team: TeamEntity)(implicit ec: ExecutionContext)
  : Future[Option[TeamEntity]] = {
    Future {
      val column = Team.column
      /****  I want to simulate some exception was thrown here ***/
      val newId = Team.createWithNamedValues(
        column.name -> team.name
      )
      if (newId.isValidLong) Option(team.copy(id = newId)) else None
    }
  }

這是輸出：

[info] - should return NOT created message if exception thrown *** FAILED ***
[info]   java.lang.Exception:
 should return updated message if collaborator team create success *** FAILED ***
[info]   org.mockito.exceptions.misusing.UnfinishedStubbingException: 

Unfinished stubbing detected here:
.g. thenReturn() may be missing.
[info] Examples of correct stubbing:
[info]     when(mock.isOk()).thenReturn(true);
[info]     when(mock.isOk()).thenThrow(exception);
[info]     doThrow(exception).when(mock).someVoidMethod();
[info] Hints:
[info]  1. missing thenReturn()
[info]  2. you are trying to stub a final method, you naughty developer!
[info]  3: you are stubbing the behaviour of another mock inside before 'thenReturn' instruction if completed

我試圖用thenThrow(new Exception)替換thenReturn(Future.failed.. thenThrow(new Exception)但無法處理錯誤ava.lang.AssertionError: assertion failed: timeout (3 seconds) during expectMsg while waiting for

Answer 1

您不想將Exception 拋出到Future.failed內部，只需在其中創建它即可。 調用真實存儲庫時發生的情況是，在計算 Future的結果時引發了異常，然后將其捕獲並放置在Failure實例中，而不是將成功的計算結果放置在Success實例中。 所以：

when(repository.create(any[Team])(same(ec))).thenReturn(Future.failed(new Exception(...)))

應該做的工作。