CirceSupport.scala

trait CirceSupport {
  import io.circe.jawn.decode
  import akka.http.scaladsl.model.ContentTypes._

  implicit def unmarshaller[A: Decoder]: FromEntityUnmarshaller[A] =
    Unmarshaller.stringUnmarshaller
      .forContentTypes(`application/json`)
      .flatMap { _ => _ => body =>
        decode[A](body)
          .fold(Future.failed, Future.successful)
      }

  implicit def marshaller[A: Encoder](implicit printer: Printer = Printer.noSpaces): ToEntityMarshaller[A] =
    Marshaller.withFixedContentType(`application/json`) { a: A =>
      HttpEntity(`application/json`, printer.pretty(a.asJson))
    }

}