Scala DV Client PoC — evaluation, typed get, exposure logging (Scala 3)

test3.scala

//> using scala 3.5
//> using jar "dv_3.jar"
//> using dep "org.typelevel::cats-core:2.12.0"
//> using dep "org.typelevel::cats-effect:3.5.4"
//> using dep "com.lihaoyi::ujson:4.0.0"
//> using dep "com.thesamet.scalapb::scalapb-runtime:1.0.0-alpha.3"

import cats.effect.{IO, IOApp, Resource}
import cats.syntax.all.*
import com.doordash.dv.DVClient
import com.doordash.dv.entity.*
import com.doordash.dv.exposure.*
import scala.concurrent.duration.*

object Test3 extends IOApp.Simple:

  val emitter: Resource[IO, ExposureEmitter[IO]] =
    Resource.pure(new ExposureEmitter[IO]:
      def emit(events: Vector[ExposureEvent]): IO[Unit] =
        IO.println(s"  [exposure] ${events.size} events: ${events.map(e => s"${e.experimentName.value}=${e.variantName.value}").mkString(", ")}")
    )

  val client: Resource[IO, DVClient[IO]] =
    DVClient.withExposureLogging[IO](
      configDir      = ConfigDir("configs"),
      reloadInterval = 30.seconds,
      emitter        = emitter
    )

  def run: IO[Unit] =
    client.use { dv =>
      val props = Properties.empty
        .setString(PropertyKey("country"), "US")
        .setRandomizationKey(RandomizationKey("user-12345"))

      for
        _ <- IO.println("=== Scala 3 Test ===")
        e1 <- dv.evaluate(DVName("dv_1"), props)
        _ <- IO.println(s"  dv_1: variant=${e1.variant.name.value} inRollout=${e1.inRollout}")
        e2 <- dv.evaluate(DVName("dv_2"), props)
        _ <- IO.println(s"  dv_2: variant=${e2.variant.name.value}")
        v <- dv.get[String](DVName("dv_3"), props, fallback = "default")
        _ <- IO.println(s"  dv_3: get[String]=$v")
        r <- dv.evaluateSet(DVName("dv_1"), props)
        _ <- IO.println(s"  evaluateSet: ${r.evaluationSets.size} sets")
        m <- dv.get[Boolean](DVName("missing"), props, fallback = false)
        _ <- IO.println(s"  missing: fallback=$m")
        _ <- IO.println("  waiting for exposure flush...")
        _ <- IO.sleep(6.seconds)
        _ <- IO.println("=== Scala 3 PASSED ===")
      yield ()
    }