Klaxon throws exceptions after minifying (w/ Proguard)

When Klaxon class names were minified, it could not find the DefaultConverter’s method toJson().

After adding the following rules to ProGuard, it throws a different exception:

-keep public class kotlin.reflect.jvm.internal.impl.** { public *; }
-keep class com.beust.klaxon.** { *; }
-keep interface com.beust.klaxon.** { *; }

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.bleh.application/com.bleh.application.WhateverActivity}: java.lang.ClassCastException: java.lang.String cannot be cast to com.beust.klaxon.JsonObject

The application works perfectly when I turn minify off. Any ideas?

[spreelanka]

@Tarpsvo try adding

-keep class kotlin.Metadata { *; }

this is what worked with minify for my project:

# Klaxon
-keep public class kotlin.reflect.jvm.internal.impl.** { public *; }
-keep class com.beust.klaxon.** { *; }
-keep interface com.beust.klaxon.** { *; }
-keep class kotlin.Metadata { *; }

#data models
-keep class com.example.mydatamodels.** { *;}

[cbeust]

Note that the error might be coming from a converter outside of the com.beust.klaxon package. If you wrote any custom converter, make sure to keep these classes too.