plugins/kotlinx-serialization/testData/diagnostics/NullabilityIncompatible.kt

// FIR_IDENTICAL
// WITH_STDLIB
// FILE: test.kt
import kotlinx.serialization.*
import kotlinx.serialization.descriptors.*
import kotlinx.serialization.encoding.*

@Serializable(NopeNullableSerializer::class)
class Nope {}

class NopeNullableSerializer: KSerializer<Nope?> {
    override val descriptor: SerialDescriptor get() = TODO()
    override fun deserialize(decoder: Decoder): Nope? = TODO()
    override fun serialize(encoder: Encoder, value: Nope?) = TODO()
}

@Serializable
class Foo(val foo: <!SERIALIZER_NULLABILITY_INCOMPATIBLE("NopeNullableSerializer; Nope")!>Nope<!>)