scala - 如何正确使用 Akka-TestKit TestProbe？

Question

我从 http://doc.akka.io/docs/akka/snapshot/scala/testing.html#Using_Multiple_Probe_Actors 扩展了示例.

import akka.actor._
import akka.testkit.{TestProbe, TestKit}
import org.scalatest.{Suites, BeforeAndAfter, BeforeAndAfterAll, FlatSpecLike}
import scala.concurrent.duration._

class TestProbesTestSuites extends Suites(new TestProbesTest)

class TestProbesTest extends TestKit(ActorSystem("TestProbesTestSystem")) with FlatSpecLike with BeforeAndAfterAll with BeforeAndAfter {
  override def afterAll: Unit = {
    TestKit.shutdownActorSystem(system)
  }

  "A TestProbeTest" should "test TestProbes" in {
    val actorRef = system.actorOf(Props[TestActor], "TestActor")
    val tester1 = TestProbe()
    val tester2 = TestProbe()

    Thread.sleep(500.milliseconds.toMillis)

    actorRef ! (tester1.ref, tester2.ref)
    // When you comment the next line the test fails
    tester1.expectMsg(500.milliseconds, "Hello")
    tester2.expectMsg(500.milliseconds, "Hello")

    // Alternative test
//    Thread.sleep(500.milliseconds.toMillis)
//    tester1.expectMsg(0.milliseconds, "Hello")
//    tester2.expectMsg(0.milliseconds, "Hello")
    ()
  }
}

class TestActor extends Actor with ActorLogging {
  override def receive: Receive = {
    case (actorRef1: ActorRef, actorRef2: ActorRef) => {
      // When you change the schedule time in the next line to 100.milliseconds the test fails
      context.system.scheduler.scheduleOnce(400.milliseconds, actorRef1,  "Hello")(context.system.dispatcher)
      context.system.scheduler.scheduleOnce(800.milliseconds, actorRef2,  "Hello")(context.system.dispatcher)
    }
    case x => log.warning(x.toString)
  }
}

我不认为这是测试的正确或良好用法。
当我删除 tester1.expectMsg(500.milliseconds, "Hello")测试失败，
所以tester2的测试依赖于tester1的测试。在我看来这很糟糕。

也在换线 context.system.scheduler.scheduleOnce(400.milliseconds, actorRef1, "Hello")(context.system.dispatcher)延迟 100 毫秒让测试失败。所以测试消息 2 取决于发送消息 1。在我看来，这也很糟糕。

为了解决这个问题，我会在发送消息后添加一个 Thread.sleep 并将 #expectMsg 的等待时间更改为 0 毫秒。 Thread.sleep 在测试中对我来说也不好看，但我认为它在 actor 测试中是必须的。这是正确的方法吗？

我认为 TestProbe 是为测试多个 Actor 而设计的。但是对我来说，在测试多个参与者时，#expectMsg 的等待时间参数是非常无用的。

欢迎提出任何意见。

Answer 1

你可以试试 within像这样阻止:

within(800.milliseconds, 900.milliseconds){
  tester1.expectMsg("Hello")
  tester2.expectMsg("Hello")
}

这样，如果您将断言注释掉 tester1测试仍然通过。