Hi folks, I have a doubt here: why Kotlin Serialization plugin doesn't generate a proguard file with...

# serialization

[Thiago]

Hi folks, I have a doubt here: why Kotlin Serialization plugin doesn't generate a proguard file with packages/classes to keep? I know this is out of library/plugin scope, but the plugin walk through classes looking for @Serializable annotation. It would be nice reusing this walk phase to "write" to a file or console packages/classes to keep. I think adding something like that will not be weight because can run in parallel with search annotation phase.
If it is totally out of scope, how can I to create a compiler plugin to do something like that?

[mbonnin]

You can use kotlinx.serialization without reflection

[mbonnin]

Why would you want to keep classes?

[mbonnin]

See https://github.com/Kotlin/kotlinx.serialization/issues/1348 for how to avoid reflection

[Thiago]

No classes at all. I mean keep code generated by serialization plugin. We are applying recommended keep rules but we a getting serialization error in release apps with our multi-module app.

[SrSouza]

There is no escape for reflection while using it with Retrofit. https://github.com/JakeWharton/retrofit2-kotlinx-serialization-converter

I'm almost sure that for Ktor this is the case as well.

[mbonnin]

I see. Well if proguard is required, there is a section in the README: https://github.com/kotlin/kotlinx.serialization#android

[mbonnin]

@Thiago can you share the error you're getting?

[Thiago]

Yes, we recently changed from old way to the new that are using proguard if.
After migration we are receiving: java.lang.IllegalArgumentException: Unable to create converter for class java.lang.Object in @Serializable classes that was working with previous proguard setup.

[Thiago]

We did rollback and we are investigating what is happening. In a multi-module app it became a mess to maintain 😅

[mbonnin]

In general there should be no need to add all @Serializable classes explicitely or list them with a plugin. The proguard rules should allow to do something like:

keep @kotlinx.serialization.Serializable class **

[mbonnin]

So that it can match all @Serializable classes

[mbonnin]

But then your error might be something completely different... Bisect on the proguard file?

[Thiago]

Yes, we were using it.

[Thiago]

We did just a migration from https://github.com/Kotlin/kotlinx.serialization/tree/v1.3.0#android to https://github.com/Kotlin/kotlinx.serialization/tree/v1.3.2#android

The second approach has broken here our serialization. We are investigating what we forgot to update

[ephemient]

if you write your own retrofit converter that statically references all your serializers, it'll work without reflection

[ephemient]

https://kotlinlang.slack.com/files/UJQB4DJF7/F02QF77GUQ2 for example

SerializerConverterFactory_kt.cpp

[FunkyMuse]

@ephemient do you have any code sample that adds all of them?

[ephemient]

"all" of them requires some sort of reflection, either runtime or compile-time