logging4s / logging4s   0.4.0

libraryDependencies ++= Seq(
  "org.logging4s" %% "logging4s-ce-3" % version,
  "org.logging4s" %% "logging4s-circe" % version
)

// Your domain
import java.util.UUID
import cats.Show
import io.circe.Encoder
import io.circe.generic.semiauto.deriveEncoder
import logging4s.core.Loggable

import logging4s.cats.instances.given
import logging4s.json.circe.instances.given

final case class User(id: UUID, name: String, age: Int)

object User:
  given Show[User]     = user => s"id=${user.id}, name=${user.name}, age=${user.age}"
  given Encoder[User]  = deriveEncoder
  given Loggable[User] = Loggable.make("user")


// Your program
import java.util.UUID
import cats.effect.std.UUIDGen
import cats.effect.{ExitCode, IO, IOApp}
import logging4s.cats.Logging

import logging4s.core.syntax.withKey

import logging4s.cats.instances.given
import logging4s.json.circe.instances.given

object CatsEffect3Example extends IOApp:

  private def createUser(name: String, age: Int): IO[User] =
    for id <- UUIDGen.randomUUID[IO]
    yield User(id, name, age)

  override def run(args: List[String]): IO[ExitCode] =
    for
      context <- IO.randomUUID.map(uuid => LoggingContext(uuid.withKey("session_id")))
      logging <- Logging.create[IO]("CatsEffect3Example", context)

      johnShow <- createUser("John Show", 22)
      _        <- logging.info("User created", johnShow)
    
      daenerys <- createUser("Daenerys Targaryen", 22)
      _        <- logging.info("User created", daenerys)
    
      _ <- logging.info("All users created", Seq(johnShow, daenerys))
    yield ExitCode.Success