scala - 使用 TestActorRef 测试 actor 崩溃

Question

我是 actors 的新手，我正在学习如何使用 TestActorRef

测试 actors

我的 Actor 代码:

package actors

import actors.GreetingActor.Hi
import akka.actor.Actor

object GreetingActor {
  case class Hi()
}

class GreetingActor extends Actor {

  var greeting = ""

  override def receive: Receive = {
    case Hi() =>
      greeting = "Hi"
    case _ =>
      throw new IllegalArgumentException("not supported message")
  }

  override def postRestart(reason: Throwable) = {
    println(s"actor is restarted because of ${reason.getMessage}")
  }
}

我确信这段代码中的一切都按我想要的方式运行，但我无法在测试中显示它。特别是我不能展示最重要的事情之一，我的 Actor 坠毁了。测试非常简单明了，我发送的消息不是 Hi() 并且应该以某种方式跟踪 actor 因 IllegalArgumentException 崩溃。我当前的测试代码:

package actors

import actors.GreetingActor.Hi
import akka.actor.ActorSystem
import akka.testkit.{TestActorRef, TestKit}
import org.scalatest.{MustMatchers, WordSpecLike}

class GreetingActorTest extends TestKit(ActorSystem("testsystem")) with WordSpecLike
  with MustMatchers with StopSystemAfterAll {

  "A Hello Actor" must {
    "change state when it receives a message, single threaded" in {
      val greetingActor = TestActorRef[GreetingActor]
      greetingActor ! Hi()
      greetingActor.underlyingActor.greeting mustBe "Hi"
    }
    "throw exception when it received unknown message, single threaded" in {
      val greetingActor = TestActorRef[GreetingActor]
      greetingActor ! "hi"
      //some code that checks that actor crashed
    }
  }

}

问题是我如何使用 TestActorRef 在测试中跟踪我的 actor 崩溃？感谢任何帮助。

Answer 1

将您的测试更改为以下内容:

"throw exception when it received unknown message, single threaded" in {
  assertThrows[IllegalArgumentException] {
      val greetingActor = TestActorRef[GreetingActor]

      greetingActor.receive("hi")
  }
}

根据 actor 文档，您需要使用 receive 以免异常被吞没:

http://doc.akka.io/docs/akka/current/scala/testing.html#The_Way_In-Between__Expecting_Exceptions