spray.json.DeserializationException: Expected String as JsString, but got {} - scala

Question

I am using Either implementation for my object because I am expecting an empty Json for one of the parameter in the object. Here is the object:
case class Record(id: String, version: Long, payload: Either[PayloadObject, String]))
I am trying to unit test this sending an empty json string which is like this:
val jsonString = """
| {
| "id":"someId"
| "version":123456
| "payload":{}
| }
|""".stripMargin
This is my unit test where I am deserializing the above json String:
{
val deserialized = Record("someId", 123456L, Right(""))
val result = jsonString.convertTo[Record]
result must equal(deserialized)
}
This is throwing error. spray.json.DeserializationException: Expected String as JsString, but got {}. How to represent the variable serialized as an empty JsString to run the unit tests? Thanks

Answer 1

If I understand your question correctly, you need to define a custom format for your case class.
case class Record(id: String, version: Long, payload: Either[JsObject, String])
object Record {
implicit val recordFormat: RootJsonReader[Record] = (json: JsValue) =>
json.asJsObject.getFields("id", "version", "payload") match {
case Seq(JsString(id), JsNumber(version), JsObject.empty) => Record(id, version.toLong, Right(""))
case Seq(JsString(id), JsNumber(version), payload: JsObject) => Record(id, version.toLong, Left(payload))
case _ => throw new Exception("Invalid record")
}
}