Hi there, I've been using `org.jetbrains.kotlin:k...

# serialization

[Rafael Tonholo]

Hi there,

I've been using org.jetbrains.kotlin:kotlin-serialization in some of my Android projects for a while, and I recently encountered an issue after enabling K2 mode on Android Studio. I started to see errors on all my classes annotated with @Serializable. The error looks like a lint error related to a missing opt-in annotation:

This declaration is opt-in and its usage should be marked with @kotlinx.serialization.InternalSerializationApi

However, it still doesn't make much sense to me.

The application builds and runs fine without any issues, so I assume it could be an Android Studio K2 mode issue. However, as the InternalSerializationApi has been always marked as @RequiresOptIn(level = RequiresOptIn.Level.ERROR), it seems like I should always have added the opt-in annotation, and I wasn't aware of, and only after K2 started to prompt errors, which is weird.

After reading the kdocs of the InternalSerializationApi, I am concerned that my app could start crashing after any updates. I am only using basic JSON serialization/deserialization and not any custom serializer or functionalities. It seems that the issue is related to the $serializer property generated by the plugin, but I am unsure about what else is marked as InternalSerializationApi or what will be affected by an internal API, potentially causing future crashes.

Initially, I thought it would be only related to sealed classes, but I also see that happening with data classes and normal classes. Funny that objects don't present the same error.

I can definitely annotate my Serializable types with the @InternalSerializationApi, however, that seems awkward...

Am I missing something? Thanks for the help

[Rafael Tonholo]

I missed adding the versions I'm using:
Kotlin: 2.0.20
kotlin-serializable: 1.7.3