@FilterNulls in Kotlin not excluding null in list

[elivity]

Hey,

I have the following issue and maybe I am just missing something:

I want to filter out null in an enum list. It works great in Java, but fails in Kotlin.

The following test reproduces the "wrong" behaviour:

import com.serjltt.moshi.adapters.DefaultOnDataMismatchAdapter
import com.serjltt.moshi.adapters.FilterNulls
import com.squareup.moshi.Moshi
import org.junit.Test

class AnimalTest {
enum class Animal {
Dog,
Cat
}

data class Animals(
    @FilterNulls val animals: List<Animal> = arrayListOf()
)

@Test
fun testMoshiEnumNullable() {
    val moshi = Moshi.Builder()
        .add(FilterNulls.ADAPTER_FACTORY)
        .add(DefaultOnDataMismatchAdapter.newFactory(Animal::class.java, null))
        .add(com.squareup.moshi.kotlin.reflect.KotlinJsonAdapterFactory())
        .build()

    val response = moshi.adapter(Animals::class.java).fromJson("""{"animals" : [
        "Dog",
        "Unknown"
    ]}""")

    assert(response != null)
    // Gets [Dog, null] instead of just [Dog]
    assert(response == Animals(animals = arrayListOf(Animal.Dog)))
}

}