Failing a scalatest when akka actor throws exception outside of the test thread

Question

I\'ve had a situation come up and bite me a few times where I\'m testing an Actor and the Actor throws an exception unexpectedly (due to a bug), but the test still passes.

Answer 1

Thinking in Actors there is also another solution: failures travel to the supervisor, so that is the perfect place to catch them and feed them into the test procedure:

val failures = TestProbe()
val props = ... // description for the actor under test
val failureParent = system.actorOf(Props(new Actor {
  val child = context.actorOf(props, "child")
  override val supervisorStrategy = OneForOneStrategy() {
    case f => failures.ref ! f; Stop // or whichever directive is appropriate
  }
  def receive = {
    case msg => child forward msg
  }
}))

You can send to the actor under test by sending to failureParent and all failures—expected or not—go to the failures probe for inspection.