How to serialize a case class with a protobuf field? - scala

Question

I have the following code that serializes a case class with an enum field to json (shorten for readability reasons). The code defines an EnumNameSerializer formatter:
import org.json4s.ext.EnumNameSerializer
import org.json4s.{DefaultFormats, Formats}
import org.json4s.jackson.JsonMethods.parse
// Class containing an enum
object EnumField extends Enumeration {
val value1, value2, value3 = Value
}
case class ClassWithProto(field: String,
enumField: EnumField)
object Serializer {
// Formatter
implicit val formats: Formats = DefaultFormats + new EnumNameSerializer(EnumField)
...
}
I'd like to replace the enum field with a protobuf field:
// Proto definition
message Value1 {}
message Value2 {}
message Value3 {}
message ProtoField {
oneof sealed_value_optional {
Value1 val1 = 1;
Value2 val2 = 2;
Value3 val3 = 3;
}
}
// New case class
case class ClassWithProto(field: String,
protoField: ProtoField)
How can I replace the old EnumNameSerializer in the formatter with a serializer that can serialize the protobuf field?
I thought about converting the protobuf class to an enum (and vice-versa) but this is an inefficient solution.