fix: support for schema codegen of nullable list / map elements

.changes/26842b1e-eda3-4dc5-b306-20cce3a1125d.json

@@ -0,0 +1,9 @@
+{
+    "id": "26842b1e-eda3-4dc5-b306-20cce3a1125d",
+    "type": "bugfix",
+    "description": "Fix schema generation for nullable lists and maps",
+    "issues": [
+        "https://github.com/awslabs/aws-sdk-kotlin/issues/1590"
+    ],
+    "module": "dynamodb-mapper"
+}

hll/dynamodb-mapper/dynamodb-mapper-schema-codegen/src/main/kotlin/aws/sdk/kotlin/hll/dynamodbmapper/codegen/annotations/rendering/SchemaRenderer.kt

@@ -175,6 +175,12 @@ internal class SchemaRenderer(
         val type = Type.from(ksType)
 
         when {
+            type.nullable -> {
+                writeInline("#T(", MapperTypes.Values.NullableConverter)
+                renderValueConverter(ksType.makeNotNullable())
+                writeInline(")")
+            }
+
             ksType.isEnum -> writeInline("#T()", MapperTypes.Values.Scalars.enumConverter(type))
 
             // FIXME Handle multi-module codegen rather than assuming nested classes will be in the same [ctx.pkg]
@@ -201,12 +207,6 @@ internal class SchemaRenderer(
 
             type.isGenericFor(Types.Kotlin.Collections.Set) -> writeInline("#T", ksType.singleArgument().setValueConverter)
 
-            type.nullable -> {
-                writeInline("#T(", MapperTypes.Values.NullableConverter)
-                renderValueConverter(ksType.makeNotNullable())
-                writeInline(")")
-            }
-
             else -> writeInline(
                 "#T",
                 when (type) {

hll/dynamodb-mapper/dynamodb-mapper-schema-generator-plugin/src/test/resources/standard-item-converters/src/Lists.kt

@@ -32,6 +32,9 @@ public data class Lists(
     var listUShort: List<UShort>,
     var listULong: List<ULong>,
     var listEnum: List<EnumAnimals>,
+    var nullableList: List<String>?,
+    var listNullableElement: List<String?>,
+    var nullableListNullableElement: List<String?>?,
 ) {
     override fun equals(other: Any?): Boolean {
         if (this === other) return true
@@ -56,6 +59,9 @@ public data class Lists(
         if (listUShort != other.listUShort) return false
         if (listULong != other.listULong) return false
         if (listEnum != other.listEnum) return false
+        if (nullableList != other.nullableList) return false
+        if (listNullableElement != other.listNullableElement) return false
+        if (nullableListNullableElement != other.nullableListNullableElement) return false
 
         return true
     }

hll/dynamodb-mapper/dynamodb-mapper-schema-generator-plugin/src/test/resources/standard-item-converters/src/Maps.kt

@@ -24,4 +24,7 @@ public data class Maps(
     var mapStringListString: Map<String, List<String>>,
     var mapStringListMapStringString: Map<String, List<Map<String, String>>>,
     var mapEnum: Map<String, EnumAnimals>,
+    var nullableMap: Map<String, String>?,
+    var mapNullableValue: Map<String, String?>,
+    var nullableMapNullableValue: Map<String, String?>?,
 )

hll/dynamodb-mapper/dynamodb-mapper-schema-generator-plugin/src/test/resources/standard-item-converters/test/ListsTest.kt

@@ -31,6 +31,9 @@ public class ListsTest {
             listUShort = listOf(UShort.MIN_VALUE, UShort.MAX_VALUE),
             listULong = listOf(ULong.MIN_VALUE, ULong.MAX_VALUE),
             listEnum = listOf(EnumAnimals.CAT, EnumAnimals.DOG, EnumAnimals.SHEEP),
+            nullableList = null,
+            listNullableElement = listOf("foo", null, "baz"),
+            nullableListNullableElement = null,
         )
 
         val item = ListsConverter.convertTo(lists)

hll/dynamodb-mapper/dynamodb-mapper-schema-generator-plugin/src/test/resources/standard-item-converters/test/MapsTest.kt

@@ -35,6 +35,9 @@ public class MapsTest {
                 ),
             ),
             mapEnum = mapOf("pet1" to EnumAnimals.CAT, "pet2" to EnumAnimals.DOG, "pet3" to EnumAnimals.SHEEP),
+            nullableMap = null,
+            mapNullableValue = mapOf("key1" to "value1", "key2" to null),
+            nullableMapNullableValue = null,
         )
 
         val item = MapsConverter.convertTo(maps)