fix namespace inheritance for sealed traits (#836)

Author: mberndt123

avro4s-core/src/main/scala/com/sksamuel/avro4s/decoders/unions.scala

@@ -17,7 +17,7 @@ object TypeUnions {
       require(schema.isUnion)
 
       val decodersByName = ctx.subtypes.map { st =>
-        val annos: Annotations = Annotations(st.annotations)
+        val annos: Annotations = new Annotations(st.annotations, st.inheritedAnnotations)
         val names = Names(st.typeInfo, annos)
         val subschema = SchemaHelper.extractTraitSubschema(names.fullName, schema)
         names.fullName -> st.typeclass.decode(subschema)

avro4s-core/src/main/scala/com/sksamuel/avro4s/encoders/unions.scala

@@ -18,7 +18,7 @@ object TypeUnions {
 
       val encoderBySubtype = ctx.subtypes.sorted(SubtypeOrdering).map(st => {
 
-        val annos: Annotations = Annotations(st.annotations)
+        val annos: Annotations = new Annotations(st.annotations, st.inheritedAnnotations)
         val names = Names(st.typeInfo, annos)
 
         val subschema: Schema = SchemaHelper.extractTraitSubschema(names.fullName, schema)

avro4s-core/src/test/scala/com/sksamuel/avro4s/record/decoder/SealedTraitDecoderTest.scala

@@ -6,6 +6,7 @@ import org.apache.avro.generic.{GenericData, GenericRecord}
 import org.apache.avro.util.Utf8
 import org.scalatest.funsuite.AnyFunSuite
 import org.scalatest.matchers.should.Matchers
+import org.apache.avro.generic.GenericContainer
 
 class SealedTraitDecoderTest extends AnyFunSuite with Matchers {
 
@@ -69,6 +70,22 @@ class SealedTraitDecoderTest extends AnyFunSuite with Matchers {
     fruitsAgain shouldBe fruits
   }
 
+  test("support round-trip for sealed traits with inheritable namespace") {
+    @AvroNamespace("spam")
+    sealed trait Foo
+    object Foo {
+      case class Bar(i: Int) extends Foo
+    }
+
+    val value: Foo = Foo.Bar(42)
+    val encoded = Encoder[Foo].encode(AvroSchema[Foo])(value)
+    encoded.asInstanceOf[GenericContainer].getSchema().getNamespace() shouldBe "spam"
+
+    val decoded = Decoder[Foo].decode(AvroSchema[Foo])(encoded)
+
+    decoded shouldBe value
+  }
+
     //test("support sealed traits of case classes") {
     //val schema = AvroSchema[Wrapper]
     //val record = new GenericData.Record(schema)