circe

I am trying to use the scala json library Circe, wrapping it in a simple trait to provide conversion to/from json for which I have the following: import io.circe.generic.auto._ import io.circe.parser._ import io.circe.syntax._ trait JsonConverter { def toJson[T](t : T) : String def fromJson[T](s: String) : T } case class CirceJsonConverter() extends JsonConverter{ override def toJson[T](t: T): String = t.asJson.noSpaces override def fromJson[T](s: String): T = decode[T](s).getOrElse(null).asInstanceOf[T] } The aim of this is to simply be able to call JsonConverter with any object and have it

Suppose I've got an ADT like this: sealed trait Event case class Foo(i: Int) extends Event case class Bar(s: String) extends Event case class Baz(c: Char) extends Event case class Qux(values: List[String]) extends Event The default generic derivation for a Decoder[Event] instance in circe expects the input JSON to include a wrapper object that indicates which case class is represented: scala> import io.circe.generic.auto._, io.circe.parser.decode, io.circe.syntax._ import io.circe.generic.auto._ import io.circe.parser.decode import io.circe.syntax._ scala> decode[Event]("""{ "i": 1000 }""")