JsonDecoder: decodeSerializableValuePolymorphic - Include currentTag in cast error

[hfhbd]

What is your use-case and why do you need this feature? JsonDecodingException: Expected class kotlinx.serialization.json.JsonObject (Kotlin reflection is not available) as the serialized body of F, but had class kotlinx.serialization.json.JsonLiteral (Kotlin reflection is not available)

This error message is not very helpful without the property name, but the name is available: currentTag.

To reproduce:

@Serializable
sealed interface F {
  @Serializable
  @SerialName("a")
  data class A(val f: F): F
}

Json.decodeFromString(F.serializer(), """{"type":"a", "f":"wrong-input"}""")

Describe the solution you'd like JsonDecodingException: Serial name f expected class kotlinx.serialization.json.JsonObject (Kotlin reflection is not available) as the serialized body of F, but had class kotlinx.serialization.json.JsonLiteral (Kotlin reflection is not available)