如何模拟儿童演员测试Akka系统？

Question

当我在Akka中有一个父演员时,在初始化时直接创建一个子actor,当我想为父actor编写单元测试时,如何用TestProbe或mock替换子actor？

例如,使用以下设计的代码示例:

class TopActor extends Actor {
  val anotherActor = context.actorOf(AnotherActor.props, "anotherActor")

  override def receive: Receive = {
    case "call another actor" => anotherActor ! "hello"
  }
}

class AnotherActor extends Actor {

  override def recieve: Receive = {
    case "hello" => // do some stuff
  }

}

如果我想为TopActor编写测试,要检查发送给AnotherActor的消息是"hello",我该如何替换AnotherActor的实现？看起来TopActor直接创建了这个子项,因此不容易访问.

Answer 1

以下方法似乎有效但直接覆盖anotherActor的val似乎有点粗糙.我想知道是否有其他更清洁/推荐的解决方案,这就是为什么我仍然问这个问题,即使我有这个有效的答案:

class TopActorSpec extends MyActorTestSuiteTrait {
  it should "say hello to AnotherActor when receive 'call another actor'" {
    val testProbe = TestProbe()

    val testTopActor = TestActorRef(Props(new TopActor {
      override val anotherActor = testProbe.ref
    }))

    testTopActor ! "call another actor"
    testProbe.expectMsg(500 millis, "hello")
  }
}