KotlinReflectionInternalError when a kotlin.time.Duration parameter has a default value

[OliverO2]

Cause: Duration is an inline class (a value class annotated with @JvmInline). There is a known bug KT-27598, causing the error when a constructor with inline class parameters is called via reflection.

Versions used:

version.com.sksamuel.hoplite..hoplite-hocon=1.4.14
version.kotlin=1.5.31 and 1.6.0
version.kotlinx.datetime=0.3.1

Source:

import com.sksamuel.hoplite.ConfigLoader
import com.sksamuel.hoplite.PropertySource
import kotlin.time.Duration
import kotlin.time.ExperimentalTime

@OptIn(ExperimentalTime::class)
data class Config constructor(
    val medium: Duration = Duration.days(1),
    val high: Duration = Duration.days(10)
)

fun main() {
    val config = ConfigLoader.Builder()
        .addPropertySource(
            PropertySource.string(
                """
                    medium = 4 hours
                """.trimIndent(), "props"
            )
        )
        .build()
        .loadConfigOrThrow<Config>()

    println("$config")
}

Build script modifications:

tasks.withType<KotlinCompile>() {
    kotlinOptions {
        jvmTarget = "11"
        freeCompilerArgs = listOf("-Xopt-in=kotlin.RequiresOptIn")
    }
}

Exception produced:

Exception in thread "main" kotlin.reflect.jvm.internal.KotlinReflectionInternalError: This callable does not support a default call: public constructor Config(medium: kotlin.time.Duration = ..., high: kotlin.time.Duration = ...) defined in Config[DeserializedClassConstructorDescriptor@22bac7bc]
	at kotlin.reflect.jvm.internal.KCallableImpl.callDefaultMethod$kotlin_reflection(KCallableImpl.kt:164)
	at kotlin.reflect.jvm.internal.KCallableImpl.callBy(KCallableImpl.kt:112)
	at com.sksamuel.hoplite.decoder.DataClassDecoder.construct(DataClassDecoder.kt:128)
	at com.sksamuel.hoplite.decoder.DataClassDecoder.safeDecode(DataClassDecoder.kt:116)
	at com.sksamuel.hoplite.decoder.NullHandlingDecoder$DefaultImpls.decode(Decoder.kt:85)
	at com.sksamuel.hoplite.decoder.DataClassDecoder.decode(DataClassDecoder.kt:28)
	at com.sksamuel.hoplite.ConfigLoader.decode(ConfigLoader.kt:400)
	at com.sksamuel.hoplite.ConfigLoader.loadConfig(ConfigLoader.kt:386)
	at MainKt.main(Main.kt:26)
	at MainKt.main(Main.kt)

[sksamuel]

I'm not sure what we can do if the bug is in the compiler.

[OliverO2]

For now, at least this issue documents the case, so that people catching the error can find out what's going on without incurring extra research effort.

I'm not sure about a solution either. Maybe we can just live with it for now. Or someone comes up with a bright idea. Maybe something like a wrapper or a delegate would do?

[sksamuel]

Hoplite supports a "poor man's" value class if you have a data class with a single parameter called "value".

…

On Tue, 16 Nov 2021 at 06:49, OliverO2 ***@***.***> wrote: For now, at least this issue documents the case, so that people catching the error can find out what's going on without incurring extra research effort. I'm not sure about a solution either. Maybe we can just live with it for now. Or someone comes up with a bright idea. Maybe something like a wrapper or a delegate would do? — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#237 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAFVSGUW7LFUQBUN3AWFJ2TUMJHOTANCNFSM5ID6Y5TQ> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>.

[OliverO2]

Good to know! With an extra level of indirection in Kotlin code, configurations can benefit from Duration default values.

This change...

data class DurationValue(val value: Duration)

data class Config constructor(
    val medium: DurationValue = DurationValue(Duration.days(1)),
    val high: DurationValue = DurationValue(Duration.days(10))
)

...makes the above example print:

Config(medium=DurationValue(value=4h), high=DurationValue(value=10d))

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[vlushn]

While this issue has a workaround, it's still very much current and will be until the compiler bug is fixed.

[OliverO2]

The required compiler fix is included in Kotlin builds build-1.7.0-Beta-3 and above, so can be expected to land in Kotlin 1.7.

[sksamuel]

Cool, thanks for letting me know.

…

On Thu, Apr 14, 2022, 7:09 AM OliverO2 ***@***.***> wrote: The required compiler fix is included in Kotlin builds build-1.7.0-Beta-3 <https://github.com/JetBrains/kotlin/releases/tag/build-1.7.0-Beta-3> and above, so can be expected to land in Kotlin 1.7. — Reply to this email directly, view it on GitHub <#237 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAFVSGXR53CC6BBXPZ74PMTVFADIBANCNFSM5ID6Y5TQ> . You are receiving this because you commented.Message ID: ***@***.***>

[OliverO2]

...as well as letting me know ;-). Ideally, such stuff could be automated, so that we could get a reminder once the Kotlin fix is released. But I am not aware of such an option.

[Virtlink]

The fix has been released in Kotlin 1.7.0. Changing the kotlin-reflect dependency to the latest 1.7.10 fixed it for me.

[sksamuel]

Closing as confirmed fixed in 1.7.x