Testing Akka Typed actors - How can I get an ActorContext?

Question

I'm trying to unit test a helper function of my actor. This helper function spawns some actors and I want to assert that this happens. In order to spawn them, the helper function needs the parent ActorContext, so that is passed in. Example:

def getDefaultInitialState(context: ActorContext[Request]): State = {
  ...
  val actor1 = context.spawn(myChildActor(), name = f"MyChild1")
  ...
  State(actor1, ...)
}

So, now I'm trying to unit test this function. In order to call it from my unit test, I need an ActorContext[Request]. I tried doing this in my test:

val testKit = BehaviorTestKit(MyParentActor()))
getDefaultInitialState(testKit.context())

Unfortunately, this doesn't work because the context() method of BehaviorTestKit is private.

How can I make this work?

Answer 1

Based on akka actor typed docs, you can also expect an effect in your test kit, which in your case, spawning an actor indeed is an effect. so I think this should probably help (abstraction of akka docs provided previously):

testKit.expectEffect(Spawned(myChildActor(), "myChild1"))

Alternatively, if your actors do not have a name, or you don't know the exact names, you can just expect anonymous actors only based on their behavior:

testKit.expectEffect(SpawnedAnonymous(myChildActor()))