我不知道巡演演员在发回什么消息，所以我创建了这个CartActor，发送消息OrderManager.ConfirmCheckoutStarted(self)。

class CartActor extends Actor {

    import CartActor._

    override def receive: PartialFunction[Any, Unit] = {
      case AddItem(item) => sender ! s"item $item added."
      case StartCheckout => sender ! OrderManager.ConfirmCheckoutStarted(self)
      case msg => println(s"I cannot understand ${msg.toString}")
    }
  }

然后我执行这个测试，检查actor引用：

import akka.actor.ActorSystem
import akka.testkit.{ImplicitSender, TestActorRef, TestKit}
import org.scalatest.BeforeAndAfterAll
import org.scalatest.matchers.should.Matchers
import org.scalatest.wordspec.AnyWordSpecLike

class CartActorDemoSpec extends TestKit(ActorSystem("CartActorDemoSpec"))
  with ImplicitSender
  with AnyWordSpecLike
  with Matchers
  with BeforeAndAfterAll {

  override def afterAll(): Unit = {
    TestKit.shutdownActorSystem(system)
  }

  import CartActorDemo._

  "The ActorsIntro actor" should {
    "send back hi replay" in {
      import CartActorDemo.CartActor._
      val cart = TestActorRef[CartActor]

      val item = "MyItem"
      cart ! AddItem(item)
      expectMsg(s"item $item added.")
      cart ! StartCheckout
      expectMsg(OrderManager.ConfirmCheckoutStarted(cart))
    }
  }
}

如果你有另一种类型的消息发送回你的case StartCheckout，你可以只是相应地改变它。