Handle unexpected discriminator values

[karayusuf]

Is there a way to decode unexpected discriminator types? Right now, an exception is raised when an unknown discriminator value is provided. I'd like to be able to deserialize the unknown type into an object rather than handling the error.

Example config

object Schema {
  sealed trait Event {
    def kind
  }

  case class CreateEvent() extends Event
  case class DeleteEvent() extends Event
  case class UnknownEvent(kind: String)

  implicit val codec = JsonCodecMaker.make[Event](CodecMakerConfig
        .withDiscriminatorFieldName(Some("kind"))
        // Totally made up config method to show the desired behavior.
        // Not trying to suggest an exact implementation.
        .withDiscriminatorFallback(UnknownEvent())) 
}

Example usage

When an unexpected value is returned, return the configured unknown event class.

val event = readFromString[Schema.Event]("""
  { 
    "kind": "asdfasdf",
    "ranom": "field"
  }
""")

event shouldBe a[Schema.UnknownEvent]
event.kind should equal("asdfasdf")

[plokhotnyuk]

@karayusuf Hi, Joe!

If I understand correctly your JSON input cannot be fully modeled by case classes or evolves faster than your model and the idea of your solution is to avoid throwing of an error for events that are not modeled yet.

Based on your code samples I wrote the possible solution here.

Please check if my solution works for your case.

[karayusuf]

Hi @plokhotnyuk . The code sample you provided looks fantastic. Will play around with it today. Thanks so much!