POC Saga

Saga.scala

class PhoneNumbersSaga(eventPublisher: EventPublisher) extends EventListener {
  private var tracker = new PhoneNumberStateTracker

  def handle(phoneNumbers: List[String]): PhoneNumberStateTracker = {
    eventPublisher.publish(AllPhoneNumberListed(phoneNumbers))
    tracker
  }

  override def execute(event: Event): Unit = event match {
    case apnc: AllPhoneNumbersCounted => tracker = PhoneNumberStateTracker(apnc.total, tracker.totalMatchedPhoneNumbers)
    case mpnc: MatchedPhoneNumbersCounted => tracker = PhoneNumberStateTracker(tracker.totalPhoneNumbersCount, mpnc.total)
  }
}

case class PhoneNumberStateTracker(totalPhoneNumbersCount: Int = 0, totalMatchedPhoneNumbers: Int = 0)

class TotalPhoneNumbersCounter(eventPublisher: EventPublisher) extends EventListener {
  override def execute(event: Event): Unit = event match {
    case apnl: AllPhoneNumberListed => eventPublisher.publish(AllPhoneNumbersCounted(apnl.phoneNumbers.length))
    case _ =>
  }
}

class PhoneNumberFinder(eventPublisher: EventPublisher) extends EventListener {
  override def execute(event: Event): Unit = event match {
    case apnl: AllPhoneNumberListed => eventPublisher.publish(PhoneNumberMatched(apnl.phoneNumbers.filter(_.startsWith("(377)"))))
    case _ =>
  }
}

class MatchedPhoneNumberCounter(eventPublisher: EventPublisher) extends EventListener {
  override def execute(event: Event): Unit = event match {
    case pnm: PhoneNumberMatched => eventPublisher.publish(MatchedPhoneNumbersCounted(pnm.phoneNumberMatched.length))
    case _ =>
  }
}

case class AllPhoneNumberListed(phoneNumbers: List[String], createdAt: LocalDateTime = LocalDateTime.now()) extends Event {
  override val name: String = AllPhoneNumberListed.name
}
object AllPhoneNumberListed {
  val name = "AllPhoneNumberListed"
}

case class AllPhoneNumbersCounted(total: Int, createdAt: LocalDateTime = LocalDateTime.now()) extends Event {
  override val name: String = "AllPhoneNumbersCounted"
}
object AllPhoneNumbersCounted {
  val name = "AllPhoneNumbersCounted"
}

case class PhoneNumberMatched(phoneNumberMatched: List[String], createdAt: LocalDateTime = LocalDateTime.now()) extends Event {
  override val name: String = "PhoneNumberMatched"
}
object PhoneNumberMatched {
  val name = "PhoneNumberMatched"
}

case class MatchedPhoneNumbersCounted(total: Int,createdAt: LocalDateTime = LocalDateTime.now()) extends Event {
  override val name: String = "MatchedPhoneNumbersCounted"
}
object MatchedPhoneNumbersCounted {
  val name = "MatchedPhoneNumbersCounted"
}

test.scala

class ProcessManagerTest extends AnyWordSpec with Matchers with BeforeAndAfterEach {
  var phoneNumberExecutive: PhoneNumbersSaga = _
  val phoneNumbers: List[String] = List("(250) 839-7238", "(978) 918-2349", "(852) 984-5973", "(587) 711-6327", "(629) 252-8255",
    "(839) 508-9619", "(552) 929-1262", "(465) 724-0980", "(377) 487-7659", "(904) 956-1940", "(548) 625-9604", "(876) 292-7936",
    "(219) 999-2245", "(304) 676-3186", "(843) 566-0331", "(271) 598-0007", "(690) 962-7373", "(847) 592-9224", "(409) 599-6776",
    "(622) 745-9762", "(224) 414-8909", "(847) 751-3825", "(636) 927-0375", "(959) 788-2139", "(626) 772-2022", "(956) 667-4484",
    "(576) 456-4131", "(631) 447-6943", "(377) 925-4951", "(632) 613-2484", "(760) 206-1358", "(332) 557-9519", "(564) 496-7593",
    "(412) 636-3117", "(234) 531-1641", "(962) 833-1373", "(932) 684-1527", "(557) 566-5129", "(688) 582-2933", "(211) 402-3009",
    "(429) 837-9386", "(373) 504-1841", "(933) 700-8717", "(858) 617-0738", "(611) 548-5575", "(358) 634-8586", "(838) 673-2329",
    "(389) 586-6491", "(482) 706-4909", "(277) 762-8216")

  override protected def beforeEach(): Unit = {
    val eventPublisher = InternalEventPublisher(new InMemoryEventStore())

    phoneNumberExecutive = new PhoneNumbersSaga(eventPublisher)
    eventPublisher.registerHandlers(Map(
      AllPhoneNumberListed.name -> Set(new TotalPhoneNumbersCounter(eventPublisher), new PhoneNumberFinder(eventPublisher)),
      AllPhoneNumbersCounted.name -> Set(phoneNumberExecutive),
      PhoneNumberMatched.name -> Set(new MatchedPhoneNumberCounter(eventPublisher)),
      MatchedPhoneNumbersCounted.name -> Set(phoneNumberExecutive)
    ))
  }

  "Saga" when {
    "Process Manager" should {
      "Count total phone numbers" in {
        val tracker = phoneNumberExecutive.handle(phoneNumbers)

        tracker.totalPhoneNumbersCount should be(50)
      }

      "Count total matched phone numbers to start with 377" in {
        val tracker = phoneNumberExecutive.handle(phoneNumbers)

        tracker.totalMatchedPhoneNumbers should be(2)
      }
    }
  }
}