Class with non properties can not be automatically serializable

[majkrzak]

Describe the bug When class constructors contains non property parameter it can not be made serializable with @Serializable annotaion

To Reproduce

@Serializable
class Foo(bar: String){
    val lol: String = bar.toLowerCase()
}

Expected behavior

Json.stringify(Foo.serializer(), Foo("LoL"))

{
    "lol": "lol"
}

Environment

• Kotlin version: 1.3.40
• Library version: 0.11.1
• Kotlin platforms: JVM
• Gradle version: Gradle 5.4.1-20190522110022+0000

[sandwwraith]

This is a conceptual limitation. See, on deserialization, when the lol field is missing, you need to recreate it as bar.toLowerCase() (properties with default values are considered optional). But you can't because you don't have bar. It's not even a field, so it has no chance to be serialized. Therefore such classes can't be serializable.

[majkrzak]

You are messing serialization and deserialization. Also class can be deserialized if delegate provides the setvalue

[sandwwraith]

Yes, I'm talking about deserialization. While 'serializable-only' concept is legit and has its use cases, this library focuses on making both processes available without corner cases, so making a class serializable and non-deserialziable at the same time is a non-goal.

Also class can be deserialized if delegate provides the setvalue

That's what I've mentioned in the issue about delegates.

[majkrzak]

Sorry, I've messed the tickets.