scala – Akka测试 – 发送者是deadLetters

class SiteCheckerSpec extends TestKit(ActorSystem("testSystem"))
                     with ImplicitSender
                     with BeforeAndAfterAll
                     with Matchers
                     with WordSpecLike {

val sites = List(
   "www.google.com","www.apple.com","www.gazeta.pl"
)

"Tested SiteChecker actor" must {
  "not receive message" in {
      val testedActor = system.actorOf(Props(new SiteChecker(sites.size) with TestActorContextCreationSupport {
          override def actorRefFactory = system
      }))

      testedActor ! SiteChecker.CheckSitesTitles(sites)
      expectNoMsg()
  }
}

override protected def afterAll(): Unit = TestKit.shutdownActorSystem(system)
}

以下演员：

class SiteChecker(workersCount: Int) extends Actor
                                    with ActorLogging
                                    with ActorContextCreationSupport {

val resultMap = mutable.HashMap.empty[String,String]
var originalSender: Option[ActorRef] = None

val workers = (
  for (i <- 1 to workersCount) yield createChildren(SiteCheckerWorker.props())
).toList

def actorRefFactory: ActorRefFactory = context

override def receive: Actor.Receive = {

case SiteChecker.CheckSitesTitles(sites) =>
  log.info(s"Sites to check $sites")
  println(sender)
  originalSender = Some(sender)
  workers.zip(sites).foreach(
    t => t._1 ! SiteCheckerWorker.CheckSiteTitle(t._2)
  )

case SiteCheckerWorker.SiteTitle(site,title) =>
  log.info(s"Obtained title $title for site $site")
  resultMap += (site -> title)
  if (resultMap.size == workers.size) {
    originalSender.get ! SiteChecker.SitesTitles(resultMap.toMap)
    context.children.foreach(context.stop)
  }
}
}

测试用例总是在传递,因为actor类中的orginalSender是deadLetters,而不是对测试发送者的引用.

以下是运行测试后的日志输出：

Actor[akka://testSystem/deadLetters]
 [INFO] [02/13/2014 18:53:59.150] [testSystem-akka.actor.default-dispatcher-2]    [akka://testSystem/user/$a] Sites to check List(www.google.com,www.apple.com,www.gazeta.pl)
 [INFO] [02/13/2014 18:53:59.154] [testSystem-akka.actor.default-dispatcher-3] [akka://testSystem/user/$a] Obtained title www.gazeta.pl for site www.gazeta.pl
 [INFO] [02/13/2014 18:53:59.157] [testSystem-akka.actor.default-dispatcher-3] [akka://testSystem/user/$a] Obtained title www.google.com for site www.google.com
 [INFO] [02/13/2014 18:53:59.158] [testSystem-akka.actor.default-dispatcher-5] [akka://testSystem/user/$a] Obtained title www.apple.com for site www.apple.com
 [INFO] [02/13/2014 18:53:59.163] [testSystem-akka.actor.default-dispatcher-4] [akka://testSystem/deadLetters] Message [actor.site.SiteChecker$SitesTitles] from  Actor[akka://testSystem/user/$a#735871082] to Actor[akka://testSystem/deadLetters] was not delivered. [1] dead letters encountered. This logging can be turned off or adjusted with configuration settings 'akka.log-dead-letters' and 'akka.log-dead-letters-during-shutdown'.

为什么会这样？