Singleton Support breaks Singleton Support?

[ShayBox]

When updating from Jackson 2 to 3 I ran into an issue with the new default enabled singleton support, it causes loading to break for me. I tried using readValue instead of readerForUpdating, but that doesn't update the singleton either way.

package tools.shay

import com.fasterxml.jackson.annotation.JsonAutoDetect.Visibility
import com.fasterxml.jackson.annotation.JsonProperty
import com.fasterxml.jackson.annotation.PropertyAccessor
import tools.jackson.core.StreamReadFeature
import tools.jackson.databind.DeserializationFeature
import tools.jackson.databind.SerializationFeature
import tools.jackson.module.kotlin.KotlinFeature
import tools.jackson.module.kotlin.jsonMapper
import tools.jackson.module.kotlin.kotlinModule
import java.io.File
import java.io.FileNotFoundException
import java.io.FileReader
import java.io.FileWriter

interface Configurable {

    private val name get() = javaClass.simpleName

    fun save() = try {
        val fileName = "$name.json"
        val file = File(fileName)
        file.parentFile?.mkdirs()
        file.createNewFile()

        val fileWriter = FileWriter(file)
        mapper.writeValue(fileWriter, this)
        // mapper.readValue(file, this.javaClass)
    } catch (e: Exception) {
        e.printStackTrace()
    }

    fun load() = try {
        val fileName = "$name.json"
        val fileReader = FileReader(fileName)
        mapper.readerForUpdating(this).readValue(fileReader)
    } catch (e: Exception) {
        e.printStackTrace()
    }

    companion object {

        private val mapper = jsonMapper {
            addModule(kotlinModule { // This seems counter-intuitive
                enable(KotlinFeature.SingletonSupport)
            })
            disable(
                DeserializationFeature.FAIL_ON_NULL_FOR_PRIMITIVES,
                DeserializationFeature.FAIL_ON_TRAILING_TOKENS,
            )
            enable(
                SerializationFeature.INDENT_OUTPUT,
                SerializationFeature.ORDER_MAP_ENTRIES_BY_KEYS,
            )
            enable(
                StreamReadFeature.IGNORE_UNDEFINED,
                StreamReadFeature.INCLUDE_SOURCE_IN_LOCATION,
            )
            changeDefaultVisibility {
                it.withVisibility(PropertyAccessor.ALL, Visibility.NONE)
            }
        }

        fun <C : Configurable> load(config: C): C = try {
            val fileName = "${config.name}.json"
            val fileReader = FileReader(fileName)
            mapper.rebuild().addModule(kotlinModule {
                disable(KotlinFeature.SingletonSupport)
            }).build().readerForUpdating(config).readValue(fileReader)

//            val file = File(fileName)
//            file.parentFile?.mkdirs()
//            file.createNewFile()
//            mapper.readValue(file, config.javaClass)
        } catch (_: FileNotFoundException) {
            println("FileNotFoundException")
            config
        } catch (e: Exception) {
            e.printStackTrace()
            config
        }

    }

}

abstract class Widget {

    @JsonProperty
    @get:JsonProperty
    @set:JsonProperty
    var isOpened = false

}

open class Label(label: String? = null) : Widget() {

    @JsonProperty
    @get:JsonProperty
    @set:JsonProperty
    var label = label ?: this::class.simpleName

}

open class Toggle(label: String? = null) : Label(label) {

    @JsonProperty
    @get:JsonProperty
    @set:JsonProperty
    var isActive = false

}

abstract class Module : Toggle(), Configurable {

    //

}

object TestModule : Module() {

    //

}

fun main() {
    println("Writing 'TestModule' to disk, both should return 'TestModule', not 'Failed to load'")
    TestModule.save()
    TestModule.label = "Failed to load"

    TestModule.load()
    println("SingletonSupport Enabled: ${TestModule.label}")

    Configurable.load(TestModule)
    println("SingletonSupport Disabled: ${TestModule.label}")
}

This is a simpler version of the layout in my project that's able to reproduce it, both should return 'TestModule', but the with SingleSupport enabled it returns 'Failed to load'.

[ShayBox]

Additionally, if I add an Input widget and create one in the TestModule, when loading it fails because it's missing default from the json file, but I don't want it to be saved/loaded, or I would have annotated it, I want it to remain what it is already from the constructor.

open class Input(label: String, default: String) : Label(label) {

    @JsonProperty
    @get:JsonProperty
    @set:JsonProperty
    var value = default

}

object TestModule : Module() {

    @JsonProperty
    @get:JsonProperty
    @set:JsonProperty
    var testInput = Input("Test Input", "Default Input")

}

tools.jackson.module.kotlin.KotlinInvalidNullException: Instantiation of [simple type, class tools.shay.Input] value failed for JSON property default due to missing (therefore NULL) value for creator parameter default which is a non-nullable type
 at [Source: (FileReader); line: 9, column: 3] (through reference chain: tools.shay.TestModule["testInput"]->tools.shay.Input["default"])
	at tools.jackson.module.kotlin.KotlinValueInstantiator.createFromObjectWith(KotlinValueInstantiator.kt:95)
	at tools.jackson.databind.deser.bean.PropertyBasedCreator.build(PropertyBasedCreator.java:271)
	at tools.jackson.databind.deser.bean.BeanDeserializer._deserializeUsingPropertyBased(BeanDeserializer.java:703)
	at tools.jackson.databind.deser.bean.BeanDeserializerBase.deserializeFromObjectUsingNonDefault(BeanDeserializerBase.java:1417)
	at tools.jackson.databind.deser.bean.BeanDeserializer.deserializeFromObject(BeanDeserializer.java:480)
	at tools.jackson.databind.deser.bean.BeanDeserializer.deserialize(BeanDeserializer.java:200)
	at tools.jackson.databind.deser.impl.MethodProperty.deserializeAndSet(MethodProperty.java:120)
	at tools.jackson.databind.deser.bean.BeanDeserializer.deserialize(BeanDeserializer.java:286)
	at tools.jackson.databind.deser.DeserializationContextExt.readRootValue(DeserializationContextExt.java:267)
	at tools.jackson.databind.ObjectReader._bindAndClose(ObjectReader.java:1646)
	at tools.jackson.databind.ObjectReader.readValue(ObjectReader.java:1188)
	at tools.shay.Configurable$Companion.load(Main.kt:70)
	at tools.shay.MainKt.main(Main.kt:147)
	at tools.shay.MainKt.main(Main.kt)