Akka/Scala example source code file (TestProbeSpec.scala)

This example Akka source code file (TestProbeSpec.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Akka and Scala source code examples by using tags.

All credit for the original source code belongs to akka.io; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Akka tags/keywords

a, actorref, akka, akkaspec, assertionerror, autopilot, concurrent, defaulttimeout, string, terminated, test, testactor, testing, testprobe, time, utilities

The TestProbeSpec.scala Akka example source code

package akka.testkit

import language.postfixOps

import org.scalatest.WordSpec
import org.scalatest.Matchers
import org.scalatest.{ BeforeAndAfterEach, WordSpec }
import akka.actor._
import scala.concurrent.{ Future, Await }
import scala.concurrent.duration._
import akka.pattern.ask
import scala.util.Try

@org.junit.runner.RunWith(classOf[org.scalatest.junit.JUnitRunner])
class TestProbeSpec extends AkkaSpec with DefaultTimeout {

  "A TestProbe" must {

    "reply to futures" in {
      val tk = TestProbe()
      val future = tk.ref ? "hello"
      tk.expectMsg(0 millis, "hello") // TestActor runs on CallingThreadDispatcher
      tk.lastMessage.sender ! "world"
      future should be('completed)
      Await.result(future, timeout.duration) should be("world")
    }

    "reply to messages" in {
      val tk1 = TestProbe()
      val tk2 = TestProbe()
      tk1.ref.!("hello")(tk2.ref)
      tk1.expectMsg(0 millis, "hello")
      tk1.lastMessage.sender ! "world"
      tk2.expectMsg(0 millis, "world")
    }

    "properly send and reply to messages" in {
      val probe1 = TestProbe()
      val probe2 = TestProbe()
      probe1.send(probe2.ref, "hello")
      probe2.expectMsg(0 millis, "hello")
      probe2.lastMessage.sender ! "world"
      probe1.expectMsg(0 millis, "some hint here", "world")
    }

    def assertFailureMessageContains(expectedHint: String)(block: ⇒ Unit) {
      Try {
        block
      } match {
        case scala.util.Failure(e: AssertionError) ⇒
          if (!(e.getMessage contains expectedHint))
            fail(s"failure message did not contain hint! Was: ${e.getMessage}, expected to contain $expectedHint")
        case scala.util.Failure(oth) ⇒
          fail(s"expected AssertionError but got: $oth")
        case scala.util.Success(result) ⇒
          fail(s"expected failure but got: $result")
      }
    }

    "throw AssertionError containing hint in its message if max await time is exceeded" in {
      val probe = TestProbe()
      val hint = "some hint"

      assertFailureMessageContains(hint) {
        probe.expectMsg(0 millis, hint, "hello")
      }
    }

    "throw AssertionError containing hint in its message if received message doesn't match" in {
      val probe = TestProbe()
      val hint = "some hint"

      assertFailureMessageContains(hint) {
        probe.ref ! "hello"
        probe.expectMsg(0 millis, hint, "bye")
      }
    }

    "have an AutoPilot" in {
      //#autopilot
      val probe = TestProbe()
      probe.setAutoPilot(new TestActor.AutoPilot {
        def run(sender: ActorRef, msg: Any): TestActor.AutoPilot =
          msg match {
            case "stop" ⇒ TestActor.NoAutoPilot
            case x      ⇒ testActor.tell(x, sender); TestActor.KeepRunning
          }
      })
      //#autopilot
      probe.ref ! "hallo"
      probe.ref ! "welt"
      probe.ref ! "stop"
      expectMsg("hallo")
      expectMsg("welt")
      probe.expectMsg("hallo")
      probe.expectMsg("welt")
      probe.expectMsg("stop")
      probe.ref ! "hallo"
      probe.expectMsg("hallo")
      testActor ! "end"
      expectMsg("end") // verify that "hallo" did not get through
    }

    "be able to expect primitive types" in {
      for (_ ← 1 to 7) testActor ! 42
      expectMsgType[Int] should be(42)
      expectMsgAnyClassOf(classOf[Int]) should be(42)
      expectMsgAllClassOf(classOf[Int]) should be(Seq(42))
      expectMsgAllConformingOf(classOf[Int]) should be(Seq(42))
      expectMsgAllConformingOf(5 seconds, classOf[Int]) should be(Seq(42))
      expectMsgAllClassOf(classOf[Int]) should be(Seq(42))
      expectMsgAllClassOf(5 seconds, classOf[Int]) should be(Seq(42))
    }

    "be able to ignore primitive types" in {
      ignoreMsg { case 42 ⇒ true }
      testActor ! 42
      testActor ! "pigdog"
      expectMsg("pigdog")
    }

    "watch actors when queue non-empty" in {
      val probe = TestProbe()
      // deadLetters does not send Terminated
      val target = system.actorOf(Props(new Actor {
        def receive = Actor.emptyBehavior
      }))
      system.stop(target)
      probe.ref ! "hello"
      probe watch target
      probe.expectMsg(1.seconds, "hello")
      probe.expectMsg(1.seconds, Terminated(target)(false, false))
    }

  }

}