Jackson serialisation fails by throwing kotlin.reflect.jvm.internal.KotlinReflectionInternalError when serializing model with empty list and minifyEnabled true

[mddanishansari]

I have minifyEnabled true in my build.gradle file and let's say I have a model

data class SomeModel(
    val numberList: List<Int>
)

It get's serialized properly when numberList variable have some value's

SomeModel(listOf(1, 2, 3))

but the serialization fails if the content of numberList is empty

SomeModel(listOf()) // or SomeModel(emptyList())

Above both cases work fine if I change code to minifyEnabled false

I serialize like this

jsonMapper.writeValueAsString(someModel)

My Jackson's JsonMapper looks like this

JsonMapper().apply {
    enable(MapperFeature.INFER_PROPERTY_MUTATORS)
    enable(MapperFeature.ACCEPT_CASE_INSENSITIVE_ENUMS)
    configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)
    registerModule(KotlinModule())
}

I even have added the class in proguard-rules.pro file

-keep  class org.package.SomeModel {
    <fields>;
}

# tried this also
-keep  class org.package.SomeModel {
    *;
}

The error log are as follows

kotlin.reflect.jvm.internal.KotlinReflectionInternalError: No accessors or field is found for property val kotlin.collections.EmptyList.serialVersionUID: kotlin.Long
	at kotlin.reflect.jvm.internal.KPropertyImplKt.computeCallerForAccessor(KPropertyImpl.kt:240)
	at kotlin.reflect.jvm.internal.KPropertyImplKt.access$computeCallerForAccessor(KPropertyImpl.kt:1)
	at kotlin.reflect.jvm.internal.KPropertyImpl$Getter$caller$2.invoke(KPropertyImpl.kt:156)
	at kotlin.reflect.jvm.internal.KPropertyImpl$Getter$caller$2.invoke(KPropertyImpl.kt:147)
	at kotlin.reflect.jvm.internal.ReflectProperties$LazyVal.invoke(ReflectProperties.java:62)
	at kotlin.reflect.jvm.internal.ReflectProperties$Val.getValue(ReflectProperties.java:31)
	at kotlin.reflect.jvm.internal.KPropertyImpl$Getter.getCaller(Unknown Source:7)
	at kotlin.reflect.jvm.ReflectJvmMapping.getJavaMethod(ReflectJvmMapping.kt:63)
	at com.fasterxml.jackson.module.kotlin.KotlinAnnotationIntrospector.getCorrespondingGetter(KotlinAnnotationIntrospector.kt:145)
	at com.fasterxml.jackson.module.kotlin.KotlinAnnotationIntrospector.hasRequiredMarker(KotlinAnnotationIntrospector.kt:110)
	at com.fasterxml.jackson.module.kotlin.KotlinAnnotationIntrospector.access$hasRequiredMarker(KotlinAnnotationIntrospector.kt:23)
	at com.fasterxml.jackson.module.kotlin.KotlinAnnotationIntrospector$hasRequiredMarker$hasRequired$1.invoke(KotlinAnnotationIntrospector.kt:40)
	at com.fasterxml.jackson.module.kotlin.KotlinAnnotationIntrospector$hasRequiredMarker$hasRequired$1.invoke(KotlinAnnotationIntrospector.kt:23)
	at com.fasterxml.jackson.module.kotlin.ReflectionCache.javaMemberIsRequired(ReflectionCache.kt:56)
	at com.fasterxml.jackson.module.kotlin.KotlinAnnotationIntrospector.hasRequiredMarker(KotlinAnnotationIntrospector.kt:33)
	at com.fasterxml.jackson.databind.introspect.AnnotationIntrospectorPair.hasRequiredMarker(AnnotationIntrospectorPair.java:318)
	at com.fasterxml.jackson.databind.introspect.AnnotationIntrospectorPair.hasRequiredMarker(AnnotationIntrospectorPair.java:318)
	at com.fasterxml.jackson.databind.introspect.POJOPropertyBuilder.getMetadata(POJOPropertyBuilder.java:229)
	at com.fasterxml.jackson.databind.introspect.POJOPropertiesCollector._anyIndexed(POJOPropertiesCollector.java:1197)
	at com.fasterxml.jackson.databind.introspect.POJOPropertiesCollector._sortProperties(POJOPropertiesCollector.java:1099)
	at com.fasterxml.jackson.databind.introspect.POJOPropertiesCollector.collectAll(POJOPropertiesCollector.java:425)
	at com.fasterxml.jackson.databind.introspect.POJOPropertiesCollector.getJsonValueAccessor(POJOPropertiesCollector.java:227)
	at com.fasterxml.jackson.databind.introspect.BasicBeanDescription.findJsonValueAccessor(BasicBeanDescription.java:258)
	at com.fasterxml.jackson.databind.ser.BasicSerializerFactory.findSerializerByAnnotations(BasicSerializerFactory.java:391)
	at com.fasterxml.jackson.databind.ser.BasicSerializerFactory.buildCollectionSerializer(BasicSerializerFactory.java:705)
	at com.fasterxml.jackson.databind.ser.BasicSerializerFactory.buildContainerSerializer(BasicSerializerFactory.java:647)
	at com.fasterxml.jackson.databind.ser.BeanSerializerFactory._createSerializer2(BeanSerializerFactory.java:200)
	at com.fasterxml.jackson.databind.ser.BeanSerializerFactory.createSerializer(BeanSerializerFactory.java:169)
	at com.fasterxml.jackson.databind.SerializerProvider._createUntypedSerializer(SerializerProvider.java:1473)
	at com.fasterxml.jackson.databind.SerializerProvider._createAndCacheUntypedSerializer(SerializerProvider.java:1441)
	at com.fasterxml.jackson.databind.SerializerProvider.findPrimaryPropertySerializer(SerializerProvider.java:651)
	at com.fasterxml.jackson.databind.ser.impl.PropertySerializerMap.findAndAddPrimarySerializer(PropertySerializerMap.java:72)
	at com.fasterxml.jackson.databind.ser.BeanPropertyWriter._findAndAddDynamic(BeanPropertyWriter.java:895)
E/AndroidRuntime:     at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:706)
	at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:770)
	at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178)
	at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider._serialize(DefaultSerializerProvider.java:480)
	at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:319)
	at com.fasterxml.jackson.databind.ObjectMapper._writeValueAndClose(ObjectMapper.java:4485)
	at com.fasterxml.jackson.databind.ObjectMapper.writeValueAsString(ObjectMapper.java:3740)
	at org.nvest.BiTool.test1(BiTool.kt:173)
	at org.bharti.axa.ui.HomeScreenActivity$onCreate$4.onClick(HomeScreenActivity.kt:92)
	at android.view.View.performClick(View.java:7509)
	at android.view.View.performClickInternal(View.java:7486)
	at android.view.View.access$3600(View.java:841)
	at android.view.View$PerformClick.run(View.java:28709)
	at android.os.Handler.handleCallback(Handler.java:938)
	at android.os.Handler.dispatchMessage(Handler.java:99)
	at android.os.Looper.loop(Looper.java:236)
	at android.app.ActivityThread.main(ActivityThread.java:8060)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:656)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:967)

I personally feel like this is the Kotlin Reflection's issue but I'm not sure and I also have created a StackOverflow question for this https://stackoverflow.com/q/68511430/3486601

[mddanishansari]

This issue has been resolved on StackOverflow. There seems to be a bug in R8 in AGP 4.1.3 upgrading to 4.2.2 solved the issue

For more detail about the bug, check this SO answer https://stackoverflow.com/a/68521243/3486601