BenLovesFinch.scala

import io.finch._
import com.twitter.finagle.http.Status

import io.circe._
import io.circe.generic.auto._
import io.finch.circe._

// Here we tell Finch how to encode exceptions to send them over the wire.
val e: Encoder[Exception] = Encoder.instance {
  case ce: MyError => MyError.jsonEncoder(ce)
  case t: Throwable => Json.obj("message" -> Json.string(t.getMessage))
}

// Here we _handle_ errors - handling is only about whether or not we'll send a remote client
// this excpeption over the wire. Unhandled exceptions are converted into 500s without payloads.
(ping :+: ep1 :+: ep2 :+: ep3 :+: ep4).handle {
  case ce: MyError => Output.failure(ce, ce.status)
  case t: Throwable => 
    logger.warn("Unhandled exception: ", t)
    Output.failure(new Exception(t), Status.InternalServerError )
}.toService