Quill encoder/decoder with play-json

jsonb.scala

  def jsEncoder[A](implicit w: Writes[A @@ SerializedInDB]): Encoder[A] = encoder[A](
    java.sql.Types.OTHER,
    (index: Index, value: A, row: PrepareRow) =>
      row.setObject(index, writeJS(value), java.sql.Types.OTHER)
  )

  def jsOptEncoder[A](implicit w: Writes[A @@ SerializedInDB]): Encoder[Option[A]] = encoder[Option[A]](
    java.sql.Types.OTHER,
    (index: Index, maybeValue: Option[A], row: PrepareRow) => {
      val json = maybeValue.fold2(null, a => writeJS(a)(w))
      row.setObject(index, json, java.sql.Types.OTHER)
    }
  )

  def jsDecoder[A](implicit r: Reads[A @@ SerializedInDB], ct: ClassTag[A @@ SerializedInDB]): Decoder[A] =
    decoder[A] { row: ResultRow => index: Index =>
      val pgObj = row.getObject(index).asInstanceOf[PGobject]
      if (pgObj == null) throw new Exception(s"JSON is null for column $index in ${row.asString}")
      parseJS(pgObj)
    }

  def jsOptDecoder[A](implicit r: Reads[A @@ SerializedInDB], ct: ClassTag[A @@ SerializedInDB]): Decoder[Option[A]] =
    decoder[Option[A]] { row: ResultRow => index: Index =>
      val pgObj = row.getObject(index).asInstanceOf[PGobject]
      if (pgObj == null) None
      else Some(parseJS(pgObj))
    }

  private[this] def writeJS[A](a: A)(implicit w: Writes[A @@ SerializedInDB]) =
    Json.stringify(w.writes(SerializedInDB.tag(a)))

  private[this] def parseJS[A](pgObj: PGobject)(implicit r: Reads[A], ct: ClassTag[A]): A = {
    val jsString = pgObj.getValue
    val js = Json.parse(jsString)
    r.reads(js) match {
      case JsSuccess(value, _) => value
      case err: JsError => throw new Exception(
        s"Can't parse JSON as ${ct.runtimeClass.getName}: ${JsError.toJson(err)}\n\nJson: $jsString"
      )
    }
  }