FiberTrackingService.scala

object FiberTracking {
  type FiberTracking = Has[FiberTracking.Service]

  trait Service {
    def fibers: UIO[Chunk[Fiber.Runtime[Any, Any]]]
  }

  def fibers: URIO[FiberTracking, Chunk[Fiber.Runtime[Any, Any]]] =
    ZIO.accessM(_.get.fibers)

  def make(supervisor: Supervisor[Chunk[Fiber.Runtime[Any, Any]]]): FiberTracking =
    Has(new Service {
      override def fibers: UIO[Chunk[Fiber.Runtime[Any, Any]]] = supervisor.value
    })
}