Incrementing server using a different route for each request based on updating a `Ref`

IncrementingServer.scala

import org.http4s.circe._
import org.http4s.dsl.io._
import org.http4s.implicits._
import org.http4s.server.blaze.BlazeServerBuilder
import org.http4s.{ HttpApp, HttpRoutes, Request }

import cats.data.Kleisli
import cats.effect._
import cats.effect.concurrent.Ref
import cats.implicits._

object IncrementingServer extends IOApp {
  def ltRouteK(ref: Ref[IO, (Int, HttpApp[IO])]): HttpApp[IO] = Kleisli { request: Request[IO] =>
    ref.access.flatMap {
      case ((oldI, oldRoute), setter) =>
        oldRoute.run(request)
          .flatTap { _ =>
            setter((oldI + 1, counterRoute(oldI + 1)))
          }
    }
  }

  def counterRoute(i: Int): HttpApp[IO] = HttpRoutes.of[IO] {
    case GET -> Root / "tick" => Ok(s"This has been hit $i times")
  }.orNotFound

  override def run(args: List[String]): IO[ExitCode] = {
    Ref[IO].of((0, counterRoute(0))).flatMap { ref =>
      BlazeServerBuilder[IO]
        .bindHttp(8080, "0.0.0.0")
        .withHttpApp(ltRouteK(ref))
        .serve //We want an infinite stream so the application doesn't terminate early
        .compile
        .drain
    }.as(ExitCode.Success)
  }
}