CODEWITHSUNDEEP
scalaunit-testingakkaakka-testkit
Reeebuuk
Reeebuuk

Reputation: 1381

Mocking child actor in Akka

I'm trying to write unit tests for my actor and am stuck on basic mocking. PriceAggregateActor is using akka persistence and I don't want to pass in all the conf for it and would like to mock it completely.

This is the actor that I want to test

object CommandPriceActor {
  def apply() = Props(classOf[CommandPriceActor], PriceAggregateActor())
}

class CommandPriceActor(priceAggregateActorProps: Props) extends Actor with ActorLogging {

  val priceAggregateActor = context.actorOf(priceAggregateActorProps, "priceAggregateActor")

So in my tests I'm trying to do something like: 

class CommandPriceActorTest extends TestKit(ActorSystem("test-benefits",
  ConfigFactory.parseString("""akka.loggers = ["akka.testkit.TestEventListener"] """))) with FlatSpecLike with Matchers
  with BeforeAndAfterAll with Eventually{

  class MockedChild extends Actor {
    def receive = {
      case _ => lala
    }
  }

  val probe = TestProbe()
  val commandPriceActor = TestActorRef(new CommandPriceActor(Props[MockedChild]))

I'm always getting:

Caused by: java.lang.IllegalArgumentException: no matching constructor found on class CommandPriceActorTest$MockedChild for arguments []

Why is it complaining about mockedChild? It shouldn't take any constructor arguments.

Upvotes: 3

Views: 735

Answers (1)

iain
iain

Reputation: 10928

This is because MockedChild is a child actor of your test. The missing constructor argument is the reference to the test (which is the parent class).

You have three options:

  1. Pass the reference to this into Props
  2. Use the named parameter form of Props
  3. Make MockedChild a top level class (or member of an object)

Option 1

val probe = TestProbe()
val mockProps = Props(classOf[MockedChild], this)
val commandPriceActor = TestActorRef(new CommandPriceActor(mockProps))

Option 2

val probe = TestProbe()
val mockProps = Props(new MockedChild)
val commandPriceActor = TestActorRef(new CommandPriceActor(mockProps))

Option 3

val probe = TestProbe()
val mockProps = Props(new CommandPriceActorTest.MockedChild)
val commandPriceActor = TestActorRef(new CommandPriceActor(mockProps))

// ....

object CommandPriceActorTest {
  class MockedChild extends Actor {
    def receive = {
      case _ => lala
    }
  }
}

Upvotes: 1

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