`Json.parse` fails on JS for types defined in `commonTest` which extend from types defined in `commonMain`.

I am trying to upgrade my multiplatform project from Kotlin 1.3.21 and serialization 0.10.0 to Kotlin 1.3.30 and serialization 0.11.0.

After doing so, all my JVM tests pass, but many of my JS tests fail. I get errors along the lines of:

TypeError: SomeBaseClass_init is not a function

I have managed to create a small repro:

class AbstractBaseTest
{
    @Test
    fun concreteClass_test()
    {
        val concrete = ConcreteClass()
        val serialized: String = Json.stringify( ConcreteClass.serializer(), concrete )
        val parsed: ConcreteClass = Json.parse( ConcreteClass.serializer(), serialized )
    }

    @Test
    fun stubConcreteClass_test()
    {
        val concrete = StubConcreteClass()
        val serialized: String = Json.stringify( StubConcreteClass.serializer(), concrete )
        val parsed: StubConcreteClass = Json.parse( StubConcreteClass.serializer(), serialized )
    }
}

concreteClass_test() passes, but stubConcreteClass_test() fails on Json.parse:

TypeError: AbstractBase_init is not a function

The difference is ConcreteClass is defined in commonMain, whereas StubConcreteClass is defined in commonTest. The classes are just empty dummy classes.

@Serializable
abstract class AbstractBase

@Serializable
class ConcreteClass : AbstractBase()

@Serializable
class StubConcreteClass : AbstractBase()

Potentially related/relevant, since this seems a dependency issue. I copy JS test dependencies in build.gradle as follows, and this worked for the old version of Kotlin/serialization:

// JS test configuration.
// This is adapted from kotlinx-io's build file; I do not fully understand this configuration:
// https://stackoverflow.com/a/55244288/590790
apply plugin: 'com.moowork.node'
task copyJsDependencies(type: Copy, dependsOn: compileTestKotlinJs) {
    from compileKotlinJs.destinationDir
    into "${buildDir}/node_modules"

    def configuration = configurations.jsTestRuntimeClasspath
    from(files {
        configuration.collect { File file ->
            file.name.endsWith(".jar")
                    ? zipTree(file.absolutePath).matching {
                include '*.js'
                include '*.js.map' }
                    : files()
        }
    }.builtBy(configuration))
}
node {
    version = '11.12.0'
    download = true
}
task installMocha(type: NpmTask) {
    args = ['install', 'mocha']
}
task runMocha(type: NodeTask, dependsOn: [installMocha, compileTestKotlinJs, copyJsDependencies]) {
    script = file('node_modules/mocha/bin/mocha')
    args = [compileTestKotlinJs.outputFile]
}
jsTest.dependsOn runMocha

Full code is available in the repro.

[sandwwraith]

@Whathecode Fix will be available in Kotlin 1.3.41

[sandwwraith]

@Whathecode I’ve reproduced the issue and currently investigating it