Merge pull request #8 from altoo-ag/adt-enum-serialization-wip

Extend Scala 3 enum serialization to handle ADTs
altoo-ag · Nov 28, 2023 · f4d3661 · f4d3661
2 parents 0c6bcb7 + e6d4100
commit f4d3661
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Showing 2 changed files with 34 additions and 10 deletions.
diff --git a/...c/main/scala-3/io/altoo/serialization/kryo/scala/serializer/ScalaEnumNameSerializer.scala b/...c/main/scala-3/io/altoo/serialization/kryo/scala/serializer/ScalaEnumNameSerializer.scala
@@ -11,8 +11,16 @@ class ScalaEnumNameSerializer[T <: EnumValue] extends Serializer[T] {
   def read(kryo: Kryo, input: Input, typ: Class[? <: T]): T = {
     val clazz = kryo.readClass(input).getType
     val name = input.readString()
-    // using value instead of ordinal to make serialization more stable, e.g. allowing reordering without breaking compatibility
-    clazz.getDeclaredMethod("valueOf", classOf[String]).invoke(null, name).asInstanceOf[T]
+
+    try {
+      // using value instead of ordinal to make serialization more stable, e.g. allowing reordering without breaking compatibility
+      clazz.getDeclaredMethod("valueOf", classOf[String]).invoke(null, name).asInstanceOf[T]
+    } catch {
+      case _: java.lang.NoSuchMethodException =>
+        // work around Scala 3 ADT-like enums missing valueOf method
+        val objectClazz = Class.forName(clazz.getName + "$")
+        objectClazz.getDeclaredField(name).get(null).asInstanceOf[T]
+    }
   }
 
   def write(kryo: Kryo, output: Output, obj: T): Unit = {

diff --git a/...est/scala-3/io/altoo/serialization/kryo/scala/serializer/ScalaEnumSerializationTest.scala b/...est/scala-3/io/altoo/serialization/kryo/scala/serializer/ScalaEnumSerializationTest.scala
@@ -1,9 +1,7 @@
 package io.altoo.serialization.kryo.scala.serializer
 
 import com.esotericsoftware.kryo.util.{DefaultClassResolver, ListReferenceResolver}
-import io.altoo.serialization.kryo.scala.ScalaVersionSerializers
-import io.altoo.serialization.kryo.scala.serializer.{ScalaEnumNameSerializer, ScalaKryo}
-import io.altoo.serialization.kryo.scala.testkit.{AbstractKryoTest, KryoSerializationTesting}
+import io.altoo.serialization.kryo.scala.testkit.KryoSerializationTesting
 import org.scalatest.flatspec.AnyFlatSpec
 import org.scalatest.matchers.should.Matchers
 
@@ -17,34 +15,52 @@ object ScalaEnumSerializationTest {
   case class EmbeddedEnum(sample: Sample) {
     def this() = this(null)
   }
+
+  enum SimpleADT {
+    case A()
+    case B
+  }
 }
 
-class ScalaEnumSerializationTest  extends AnyFlatSpec with Matchers with KryoSerializationTesting {
+class ScalaEnumSerializationTest extends AnyFlatSpec with Matchers with KryoSerializationTesting {
   import ScalaEnumSerializationTest.*
 
   val kryo = new ScalaKryo(new DefaultClassResolver(), new ListReferenceResolver())
   kryo.setRegistrationRequired(false)
   kryo.addDefaultSerializer(classOf[scala.runtime.EnumValue], new ScalaEnumNameSerializer[scala.runtime.EnumValue])
 
-
   behavior of "Kryo serialization"
 
-  it should "reoundtrip enum" in {
+  it should "round trip enum" in {
     kryo.setRegistrationRequired(false)
 
     testSerializationOf(Sample.B)
   }
 
-  it should "reoundtrip external enum" in {
+  it should "round trip external enum" in {
     kryo.setRegistrationRequired(false)
 
     testSerializationOf(io.altoo.external.ExternalEnum.A)
   }
 
-  it should "reoundtrip embedded enum" in {
+  it should "round trip embedded enum" in {
     kryo.setRegistrationRequired(false)
     kryo.register(classOf[EmbeddedEnum], 46)
 
     testSerializationOf(EmbeddedEnum(Sample.C))
   }
+
+  it should "round trip adt enum class using generic field serializer" in {
+    kryo.setRegistrationRequired(false)
+    kryo.register(classOf[SimpleADT], 47)
+
+    testSerializationOf(SimpleADT.A)
+  }
+
+  it should "round trip adt enum object using enum serializer" in {
+    kryo.setRegistrationRequired(false)
+    kryo.register(classOf[SimpleADT], 47)
+
+    testSerializationOf(SimpleADT.B)
+  }
 }