Automatic derivation of Enumeration can't find Encoder

Question

I have a case class like this:

case class Admin(name: String, role: Role)

Role is an Enumeration

object Role extends Enumeration {
  type Role = Value
  val Manager = Value
}

When I try to:

import io.circe.generic.auto._, io.circe.syntax._

val response = Admin("John", Role.Manager).asJson.noSpaces

I get the implicit Encoder not found error.

not enough arguments for method asJson: (implicit encoder: io.circe.Encoder[Admin])io.circe.Json. Unspecified value parameter encoder.

I suppose this error is due Enumeration, so I changed to:

trait Role

object Role {
  object Manager extends Role
}

But this does't work too.

Lastly, I tried:

trait Role

object Manager extends Role

And no success. Can someone help me please? Thanks!

Answer 1

enumeratum-circe enables the following syntax

object CirceEnumeratumExample extends App {
  import enumeratum._
  import io.circe.generic.auto._, io.circe.syntax._

  sealed trait Role extends EnumEntry
  case object Role extends Enum[Role] with CirceEnum[Role] {
    case object Manager  extends Role
    case object User extends Role
    val values = findValues
  }

  case class Admin(name: String, role: Role)
  val response = Admin("John", Role.Manager).asJson.noSpaces
  println(response)
}

which outputs

{"name":"John","role":"Manager"}

where

libraryDependencies += "com.beachape" %% "enumeratum" % "1.5.13",
libraryDependencies += "com.beachape" %% "enumeratum-circe" % "1.5.21"