Behavior that fails fast for persistence failures in EventSourcedBehaviors (i.e. JournalFailureException)

FailFastEventSourcedBehavior.scala

package org.janjaali.akka.persistence.typed.behaviors

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

import java.util.UUID

object FailFastEventSourcedBehavior {

  def apply(
      eventSourcedBehavior: Behavior[Command]
  ): Behavior[Command] = {

    Behaviors.setup { ctx =>
      val eventSourcingActor = ctx.spawn(
        eventSourcedBehavior,
        s"EventSourcedBehavior$$${UUID.randomUUID()}"
      )

      ctx.watch(eventSourcingActor)

      Behaviors.receiveMessage {
        case command: Commands.CommandExpectingReply[_] =>
          eventSourcingActor ! command
          replyFailureFastOnTerminated(command.replyTo)
        case command =>
          eventSourcingActor ! command
          Behaviors.same
      }
    }
  }

  private def replyFailureFastOnTerminated[C, R](originalSender: ActorRef[StatusReply[R]]): Behavior[C] = {

    Behaviors.receiveSignal {
      case (_, Terminated(childBehavior)) =>
        originalSender ! StatusReply.Error(new Exception(s"Behavior '$childBehavior' terminated."))
        Behaviors.stopped
    }
  }
  
  /** Represents EventSourcedBehavior protocol definition */ 
  sealed trait Command

  object Commands {

    final case class CommandExpectingReply[R](
      replyTo: ActorRef[StatusReply[R]]
    ) extends Command
  }
}