I’m trying to enable minification on Android but I’m still getting `Serializer for class 'b' is not ...

# serialization

[Chris Fillmore]

I’m trying to enable minification on Android but I’m still getting Serializer for class 'b' is not found at runtime. I’ve added the ProGuard rules from here, substituting my app package name:
https://github.com/Kotlin/kotlinx.serialization#android

Is there any other step? Or something I’m missing?

[Chris Fillmore]

I’ve been using Kotlin serialization plugin v 1.5.31. I tried upgrading to 1.6.0-RC, this made no difference

[Chris Fillmore]

Kotlin version 1.5.21

[Chris Fillmore]

I have not otherwise made any configuration to proguard besides the default Android Studio provides

[Chris Fillmore]

I have no custom serializers

[ephemient]

if you use the reified extension functions StringFormat.encodeToString(value), StringFormat.decodeFromString(), similar on BinaryFormat, SerializersModule { polymorphic(..) { subclass(kclass) } } they use reflection to find the serializer.
if you instead use the member functions StringFormat.encodeToString(serializer, value), StringFormat.decodeFromString(serializer), etc. and pass in the serializer statically (e.g.MyType.serializer(), not MyType::class.serializer()) then no reflection is used, and Proguard should keep everything necessary because it's all referenced directly

[Chris Fillmore]

Oof, I use encodeToString(value) / `decodeFromString(value)`extensively

[Chris Fillmore]

Ok let me test out some changes…

[Chris Fillmore]

Thanks for responding

[ephemient]

in theory the reified helpers should not require reflection, but currently that's how it works until further compiler changes are made https://github.com/Kotlin/kotlinx.serialization/issues/1348

[russhwolf]

It might be because your serialization plugin and kotlin versions don't match.

[Chris Fillmore]

I did not realize they were tracked the same

[Chris Fillmore]

@russhwolf I did a quick check to see if matching the versions made a difference; it did not for me