Akka-Typed Actor unit tests

Question

I've been trying to learn how to test akka-typed Actors. I've been referencing various examples online. I am successful at running the sample code but my efforts to write simple unit tests fail.

Can someone point out what I'm doing wrong? My goal is to be able to write unit test that verify each behavior.

build.sbt

import Dependencies._

ThisBuild / scalaVersion := "2.13.7"
ThisBuild / version := "0.1.0-SNAPSHOT"
ThisBuild / organization := "com.example"
ThisBuild / organizationName := "example"

val akkaVersion = "2.6.18"

lazy val root = (project in file("."))
  .settings(
    name := "akkat",
    libraryDependencies ++= Seq(
      scalaTest % Test,
      "com.typesafe.akka" %% "akka-actor-typed" % akkaVersion,
      "com.typesafe.akka" %% "akka-actor-testkit-typed" % akkaVersion % Test,
      "ch.qos.logback" % "logback-classic" % "1.2.3"
    )
  )

EmotionalFunctionalActor.scala

package example

import akka.actor.typed.{ActorRef, Behavior}
import akka.actor.typed.scaladsl.Behaviors

object EmotionalFunctionalActor {

  trait SimpleThing
  object EatChocolate extends SimpleThing
  object WashDishes extends SimpleThing
  object LearnAkka extends SimpleThing
  final case class Value(happiness: Int) extends SimpleThing
  final case class HowHappy(replyTo: ActorRef[SimpleThing]) extends SimpleThing

  def apply(happiness: Int = 0): Behavior[SimpleThing] = Behaviors.receive { (context, message) =>
    message match {
      case EatChocolate =>
        context.log.info(s"($happiness) eating chocolate")
        EmotionalFunctionalActor(happiness + 1)

      case WashDishes =>
        context.log.info(s"($happiness) washing dishes, womp womp")
        EmotionalFunctionalActor(happiness - 2)

      case LearnAkka =>
        context.log.info(s"($happiness) Learning Akka, yes!!")
        EmotionalFunctionalActor(happiness + 100)

      case HowHappy(replyTo) =>
        replyTo ! Value(happiness)
        Behaviors.same

      case _ =>
        context.log.warn("Received something i don't know")
        Behaviors.same
    }
  }
}

EmoSpec.scala

package example

import akka.actor.testkit.typed.scaladsl.ActorTestKit
import akka.actor.typed.scaladsl.AskPattern.Askable
import akka.util.Timeout
import org.scalatest.BeforeAndAfterAll
import org.scalatest.flatspec.AnyFlatSpec
import org.scalatest.matchers.should.Matchers

import scala.concurrent.duration.DurationInt

class EmoSpec extends AnyFlatSpec
  with BeforeAndAfterAll
  with Matchers {

  val testKit = ActorTestKit()

  override def afterAll(): Unit = testKit.shutdownTestKit()

  "Happiness Leve" should "Increase by 1" in {
    val emotionActor = testKit.spawn(EmotionalFunctionalActor())
    val probe = testKit.createTestProbe[EmotionalFunctionalActor.SimpleThing]()

    implicit val timeout: Timeout = 2.second
    implicit val sched = testKit.scheduler
    import EmotionalFunctionalActor._

    emotionActor ! EatChocolate
    probe.expectMessage(EatChocolate)

    emotionActor ? HowHappy
    probe.expectMessage(EmotionalFunctionalActor.Value(1))

    val current = probe.expectMessageType[EmotionalFunctionalActor.Value]
    current shouldBe 1
  }
}