Testing pykka actors without ask()

[mrkrizic]

Hello, I am currently implementing actors which use a state machine to define an actor's behaviour.

Consider this small transition: Stopped -> Resetting -> Idle -> Stopped. Each time the actor changes it's state, a supervisor gets a notification.

An example of such an actor would be (I did not test this with a python interpreter):
Assume the SubActor is performing a blocking operation e.g. connecting to a server

class ExampleActor(pykka.ThreadingActor):
    def __init__(self, supervisor):
        self.machine = MyStateMachine(supervisor)
        self.sub_actor = SubActor.start()

   def on_receive(self, message):
       if message == "Reset":
           return self.machine.reset()
      elif message == "Stop":
           return self.machine.stop()
      elif message == "SubActorReady":
           return self.machine.idle()

When my actor is in the stopped state I can call reset on it. The transition to Resetting is testable using the approach from the docs. But if my Resetting state involves sending a message to other actor(s) and transitioning to Idle once they responded, this approach does not seem to work.

Is there a clean way to test this behaviour? I saw a discussion on testing here, but the mailbox checking approach just blocks my test indefinitely.