akka Actor unit testing using testkit

Question

There are many examples of using akka-testkit when the Actor being tested is responding to an ask:

//below code was copied from example link
val actorRef = TestActorRef(new MyActor)
// hypothetical message stimulating a '42' answer
val future = actorRef ? Say42
val Success(result: Int) = future.value.get
result must be(42)

But I have an Actor that does not respond to a sender; it instead sends a message to a separate actor. A simplified example being:

class PassThroughActor(sink : ActorRef) {
  def receive : Receive = {
    case _ => sink ! 42
  }
}

TestKit has a suite of expectMsg methods but I cannot find any examples of creating a test sink Actor that could expect a message within a unit test.

Is it possible to test my PassThroughActor?

Thank you in advance for your consideration and response.

You can create probes and probe actors. Just keep reading in the documentation. — Bob Dalgleish, Jun 03 '15 at 00:30
Ah, thank you. Obviously a common enough problem. Was difficult to google though, hence the question. If you submit an answer I'll vote it... — Ramón J Romero y Vigil, Jun 03 '15 at 00:37

score 2 · Accepted Answer · answered Jun 03 '15 at 10:01

2

As mentioned in the comments you can use a TestProbe to solve this:

val sink = TestProbe()
val actorRef = TestActorRef(Props(new PassThroughActor(sink.ref)))

actorRef ! "message"

sink.expectMsg(42)

answered Jun 03 '15 at 10:01

Akos Krivachy

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akka Actor unit testing using testkit

1 Answers1