I seem to be hitting an issue when reading an immutable

data class

from Mongo due to the presence of the final parameter of the constructor being of type `kotlin.jvm.internal.DefaultConstructorMarker`: I get an exception

org.springframework.data.mapping.MappingException: Parameter org.springframework.data.mapping.PreferredConstructor$Parameter@80a6e44c does not have a name!

. The parameter in question is, indeed, the

DefaultConstructorMarker

. I'm using Spring Data MongoDB

3.2.1

w/commons

2.5.1

.

Offending

data class

is :

sealed interface Availability {
    companion object {
        val CONVENTIONAL_8TO5_WITH_LUNCH_RECURRENCE: CronString = "0/30 8-12,13-17 * * MON-FRI"
        val CONVENTIONAL_8TO5_RECURRENCE: CronString = "0/30 8-17 * * MON-FRI"
        val CONVENTIONAL_9TO5_WITH_LUNCH_RECURRENCE: CronString = "0/30 9-12,13-17 * * MON-FRI"
        val CONVENTIONAL_9TO5_RECURRENCE: CronString = "0/30 9-17 * * MON-FRI"

        val DEFAULT_RECURRENCE = CONVENTIONAL_9TO5_WITH_LUNCH_RECURRENCE
        val DEFAULT_SLOT_MINUTES = 30U.toUByte()
        val DEFAULT_ALLOWED_BOOKING_COUNT = 1U.toUByte()
    }

    val handle: String
    val slotMinutes: UByte
    val allowedBookingCount: UByte
    val name: String?
    val effectivity: Interval?
}

data class RecurringAvailability(
    val recurrence: CronString = DEFAULT_RECURRENCE,
    override val handle: String = UUID.randomUUID().toString(),
    override val slotMinutes: UByte = DEFAULT_SLOT_MINUTES,
    override val allowedBookingCount: UByte = DEFAULT_ALLOWED_BOOKING_COUNT,
    override val effectivity: Interval? = null,
    override val name: String? = null,
) : Availability

(fyi,

CronString

is

typealias CronString = String

)

Figured it out. I was using Kotlin unsigned byte types, which leverage inline classes. Bug that I hit was https://github.com/spring-projects/spring-data-commons/issues/1947. Also relevant was https://github.com/spring-projects/spring-data-commons/issues/2215#issuecomment-752410346