CODEWITHSUNDEEP
scalaakka
DJ180
DJ180

Reputation: 19854

Scala: getting result of PartialFunction

My Akka actor system has some tests to verify message content 

myEventActor.expectMsgPF() {
    verifyEventPF(id)
}

def verifyEventPF(id: String): PartialFunction[Any, Any] = {
    case e : MyEvent if e.id == id => e.otherID
}

For example, we use this partial function to check that the id on the event is correct. But how do I go about getting the result of the partial function e.g. if I want to achieve the following

myEventActor.expectMsgPF() {
    var otherID = verifyEventPF(id) // How do I achieve this?
}

Is this possible?

(I am aware I don't need to use a partial function here and could use Akka TestProbe.receiveOne() but I'd like to understand how this is possible)

Upvotes: 1

Views: 59

Answers (1)

gregghz
gregghz

Reputation: 3965

Calling verfiyEventPF(id) returns a PartialFunction[Any, Any]. You have to also call the returned function (giving it input, of course): verifyEventPF(id)(event).

This is the same as the following:

val getId: PartialFunction[Any, Any] = verifyEventPF(id)
getId(event)

If you're concerned about the partial funciton not being defined for a particular input, you can check if the function is defined for a given value:

if (getId.isDefinedAt(event)) {
  getId(event)
}

Or you can lift the partial function into a total function that returns an Option:

val totalGetId: (Any => Option[Any]) = getId.lift
val result: Option[Any] = totalGetId(event)

Upvotes: 2

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