Using delegated properties in deserialization

[StefanSrf]

Your question We would like to make use of kotlins 'inheritance by delegation' feature. In the json-structure the object should be flat, i.e. not exposing the delegation. Suppressing the delegation during serialization works, but deserialization fails. Is there a way to achive this or should we raise a feature request?

Example:

class DelegateTest {
    interface SharedInterface {
        val commonString: String
    }

    data class InternalSharedDelegate(override val commonString: String) : SharedInterface

    data class ExposedObject(
        // ignore/hide the delegation in json serialization
        @param:JsonProperty(access = JsonProperty.Access.WRITE_ONLY)
        val delegate: InternalSharedDelegate,
        val otherValue: String
    ) : SharedInterface by delegate

    private val objectMapper = jsonMapper { addModule(kotlinModule()) }

    @Test
    fun `should deserialize delegated property`() {
        val exposedObject = ExposedObject(delegate = InternalSharedDelegate("a"), otherValue = "b")

        val serialized = objectMapper.writeValueAsString(exposedObject)
        assertEquals("{\"otherValue\":\"b\",\"commonString\":\"a\"}", serialized)

        // following line causes:
        // Instantiation of [simple type, class DelegateTest$ExposedObject] value failed for JSON property delegate due to missing (therefore NULL) value for creator parameter delegate which is a non-nullable type
        val deserialized: ExposedObject = objectMapper.readValue(serialized)

        assertEquals(exposedObject, deserialized)
    }
}