I’m using moshi which accesses the Kotlin default constructor of a class by reflection.

The class looks like this:

@JsonClass(generateAdapter = true)
data class AClassName(
    val threadId: String,
    val title: String? = null
)

If I use “View bytecode” in Android Studio I can see the constructor does in fact exist:

public synthetic <init>(Ljava/lang/String;Ljava/lang/String;ILkotlin/jvm/internal/DefaultConstructorMarker;)V

To try and keep it I add

-keep @com.squareup.moshi.JsonClass class * {
    <init>(...);
}

However, r8 removes it anyway, keeping only the non-synthetic constructor. Does anyone know why?