ZIO learning - playing with opaque types and zio-json / published by https://github.com/dacr/code-examples-manager #46741a15-42bc-42bf-b4c4-e067bd6ff680/9d1a18e7ed3cabb5a54dd1022412846cc86d6031

zio-learning-json-5-opaque-types.sc

// summary : ZIO learning - playing with opaque types and zio-json
// keywords : scala, zio, learning, json, pure-functional, opaque, opaque-types, @testable
// publish : gist
// authors : David Crosson
// license : Apache NON-AI License Version 2.0 (https://raw.githubusercontent.com/non-ai-licenses/non-ai-licenses/main/NON-AI-APACHE2)
// id : 46741a15-42bc-42bf-b4c4-e067bd6ff680
// created-on : 2023-05-13T14:17:51+02:00
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli $file

// ---------------------
//> using scala  "3.2.2"
//> using dep "dev.zio::zio:2.0.13"
//> using dep "fr.janalyse::zio-worksheet:2.0.13.0"
//> using dep "dev.zio::zio-json:0.5.0"
//> using options "-Yretain-trees" // When case classes are using default values
// ---------------------

import zio.*, zio.json.*, zio.worksheet.*
import java.time.OffsetDateTime

opaque type UserName = String
object UserName {
  def apply(value: String): UserName = value
  given JsonCodec[UserName]          = JsonCodec.string
}

opaque type LastSeenDateTime = OffsetDateTime
object LastSeenDateTime {
  def apply(value: OffsetDateTime): LastSeenDateTime = value
  given JsonCodec[LastSeenDateTime]                  = JsonCodec.offsetDateTime
}

case class User(
  userName: UserName,
  lastSeen: LastSeenDateTime
) derives JsonCodec

val json =
  """{
    |  "userName":"joe",
    |  "lastSeen":"2021-04-09T17:19:17.000Z"
    |}""".stripMargin

val app =
  for
    person <- ZIO.fromEither(json.fromJson[User])
    _      <- Console.printLine(person.toJsonPretty)
  yield ()

app.unsafeRun