Akka Actor isTerminated deprecated

Question

Just writing a unit test to ensure an actor shuts down under certain conditions, so I have a test like:

    val tddTestActor = TestActorRef[MyActor](Props(classOf[MyActor], "param1"))
    tddTestActor ! someMessage
    tddTestActor.isTerminated shouldBe true

I'm picking up a warning that isTerminated is deprecated. The hint recommends I use context.watch() however in a unit test I don't have a parent actor or any context to watch.

What would be the bext way to validate tddTestActor shuts down ?

Answer 1

I agree that watching is the best way to get this done. When I am testing for stop behavior, I will usually use a TestProbe as the watcher to check on my actor under test. Say I had a very simple Actor defined as follows:

class ActorToTest extends Actor{
  def receive = {
    case "foo" => 
      sender() ! "bar"
      context stop self
  }
}

Then, using specs2 in combination with akka's TestKit I could test the stop behavior like so:

class StopTest extends TestKit(ActorSystem()) with SpecificationLike with ImplicitSender{

  trait scoping extends Scope {
    val watcher = TestProbe()
    val actor = TestActorRef[ActorToTest]
    watcher.watch(actor)
  }

  "Sending the test actor a foo message" should{
    "respond with 'bar' and then stop" in new scoping{
      actor ! "foo"
      expectMsg("bar")
      watcher.expectTerminated(actor)
    }
  }

}