fix: Allow encoding null array items or null map values

src/main/kotlin/com/github/avrokotlin/avro4k/decoder/ListDecoder.kt

@@ -71,6 +71,7 @@ class ListDecoder(
  return array[index]
  }
 
+ override fun decodeNotNullMark() = array[index] != null
  override fun fieldSchema(): Schema = schema.elementType
 
  override fun decodeEnum(enumDescriptor: SerialDescriptor): Int {

src/main/kotlin/com/github/avrokotlin/avro4k/decoder/MapDecoder.kt

@@ -42,6 +42,14 @@ class MapDecoder(
 
  private fun value(): Any? = entries[index / 2].second
 
+ override fun decodeNotNullMark() : Boolean {
+ val entry = entries[index / 2]
+ return when {
+ index % 2 == 0 -> entry.first
+ else -> entry.second
+ } != null
+ }
+
  override fun decodeFloat(): Float {
  return when (val v = value()) {
  is Float -> v

src/main/kotlin/com/github/avrokotlin/avro4k/encoder/ListEncoder.kt

@@ -32,6 +32,10 @@ class ListEncoder(private val schema: Schema,
  list.add(value)
  }
 
+ override fun encodeNull() {
+ list.add(null)
+ }
+
  override fun encodeString(value: String) {
  list.add(StringToAvroValue.toValue(schema, value))
  }

src/main/kotlin/com/github/avrokotlin/avro4k/encoder/MapEncoder.kt

@@ -19,7 +19,7 @@ class MapEncoder(schema: Schema,
  CompositeEncoder,
  StructureEncoder {
 
- private val map = mutableMapOf<Utf8, Any>()
+ private val map = mutableMapOf<Utf8, Any?>()
  private var key: Utf8? = null
  private val valueSchema = schema.valueType
 
@@ -39,6 +39,14 @@ class MapEncoder(schema: Schema,
  }
  }
 
+ override fun encodeNull() {
+ val k = key
+ if (k == null) throw SerializationException("Expected key but received null value") else {
+ map[k] = null
+ key = null
+ }
+ }
+
  override fun endStructure(descriptor: SerialDescriptor) {
  callback(map.toMap())
  }

src/test/kotlin/com/github/avrokotlin/avro4k/endecode/ArrayEncoderTest.kt

@@ -7,51 +7,58 @@ import io.kotest.core.spec.style.wordSpec
 import kotlinx.serialization.Serializable
 
 class ArrayEncoderTest : WordSpec({
-  includeForEveryEncoder { arrayEncodingTests(it) }
+ includeForEveryEncoder { arrayEncodingTests(it) }
 })
 
 @Suppress("ArrayInDataClass")
 fun arrayEncodingTests(encoderToTest: EnDecoder): TestFactory {
- return wordSpec {
- "en-/decoder" should {
- "generate GenericData.Array for an Array<Boolean>" {
- @Serializable
- data class ArrayBooleanTest(val a: Array<Boolean>)
-
- val value = ArrayBooleanTest(arrayOf(true, false, true))
- encoderToTest.testEncodeDecode(value, record(value.a.asList()))
- }
- "support GenericData.Array for an Array<Boolean> with other fields" {
- @Serializable
- data class ArrayBooleanWithOthersTest(val a: String, val b: Array<Boolean>, val c: Long)
-
- val value = ArrayBooleanWithOthersTest("foo", arrayOf(true, false, true), 123L)
- encoderToTest.testEncodeDecode(
- value, record(
- "foo",
- listOf(true, false, true),
- 123L
- )
- )
- }
-
- "generate GenericData.Array for a List<String>" {
- @Serializable
- data class ListStringTest(val a: List<String>)
- encoderToTest.testEncodeDecode(
- ListStringTest(listOf("we23", "54z")), record(
- listOf("we23", "54z")
- )
- )
- }
- "generate GenericData.Array for a Set<Long>" {
- @Serializable
- data class SetLongTest(val a: Set<Long>)
-
- val value = SetLongTest(setOf(123L, 643L, 912L))
- val record = record(listOf(123L, 643L, 912))
- encoderToTest.testEncodeDecode(value, record)
- }
- }
- }
+ return wordSpec {
+ "en-/decoder" should {
+ "generate GenericData.Array for an Array<Boolean>" {
+ @Serializable
+ data class ArrayBooleanTest(val a: Array<Boolean>)
+
+ val value = ArrayBooleanTest(arrayOf(true, false, true))
+ encoderToTest.testEncodeDecode(value, record(value.a.asList()))
+ }
+ "generate GenericData.Array for an Array<Boolean?>" {
+ @Serializable
+ data class ArrayBooleanTest(val a: Array<Boolean?>)
+
+ val value = ArrayBooleanTest(arrayOf(true, null, false))
+ encoderToTest.testEncodeDecode(value, record(value.a.asList()))
+ }
+ "support GenericData.Array for an Array<Boolean> with other fields" {
+ @Serializable
+ data class ArrayBooleanWithOthersTest(val a: String, val b: Array<Boolean>, val c: Long)
+
+ val value = ArrayBooleanWithOthersTest("foo", arrayOf(true, false, true), 123L)
+ encoderToTest.testEncodeDecode(
+ value, record(
+ "foo",
+ listOf(true, false, true),
+ 123L
+ )
+ )
+ }
+
+ "generate GenericData.Array for a List<String>" {
+ @Serializable
+ data class ListStringTest(val a: List<String>)
+ encoderToTest.testEncodeDecode(
+ ListStringTest(listOf("we23", "54z")), record(
+ listOf("we23", "54z")
+ )
+ )
+ }
+ "generate GenericData.Array for a Set<Long>" {
+ @Serializable
+ data class SetLongTest(val a: Set<Long>)
+
+ val value = SetLongTest(setOf(123L, 643L, 912L))
+ val record = record(listOf(123L, 643L, 912))
+ encoderToTest.testEncodeDecode(value, record)
+ }
+ }
+ }
 }

src/test/kotlin/com/github/avrokotlin/avro4k/endecode/MapEncoderTest.kt

@@ -23,6 +23,15 @@ fun mapEncoderTests(enDecoder: EnDecoder): TestFactory {
  )
  }
 
+ "encode/decode a Map<String, Boolean?>" {
+ @Serializable
+ data class StringBooleanTest(val a: Map<String, Boolean?>)
+ enDecoder.testEncodeDecode(
+ StringBooleanTest(mapOf("a" to true, "b" to null, "c" to false)),
+ record(mapOf("a" to true, "b" to null, "c" to false))
+ )
+ }
+
  "encode/decode a Map<String, String>" {
 
  @Serializable