From a28bb37d67f992b739c1c56b0be96e654732632a Mon Sep 17 00:00:00 2001
From: Erik van Oosten <e.vanoosten@grons.nl>
Date: Mon, 9 May 2022 20:16:24 +0200
Subject: [PATCH] Add type class to derived record name

This approach has the advantage of giving each type instance a different name. This is relevant if the consumer of the schema uses code generation. The feature is copied from Avro4s.
---
 .../src/main/scala-2/vulcan/generic/package.scala    |  5 ++++-
 .../src/main/scala-3/vulcan/generic/package.scala    |  9 +++++++--
 .../vulcan/generic/GenericDerivationCodecSpec.scala  | 12 ++++++++++++
 .../vulcan/generic/examples/CaseClassTypeClass.scala | 10 ++++++++++
 .../examples/CaseClassTypeClassAvroName.scala        | 11 +++++++++++
 5 files changed, 44 insertions(+), 3 deletions(-)
 create mode 100644 modules/generic/src/test/scala/vulcan/generic/examples/CaseClassTypeClass.scala
 create mode 100644 modules/generic/src/test/scala/vulcan/generic/examples/CaseClassTypeClassAvroName.scala

diff --git a/modules/generic/src/main/scala-2/vulcan/generic/package.scala b/modules/generic/src/main/scala-2/vulcan/generic/package.scala
index 34c6f166..7aa2402f 100644
--- a/modules/generic/src/main/scala-2/vulcan/generic/package.scala
+++ b/modules/generic/src/main/scala-2/vulcan/generic/package.scala
@@ -56,12 +56,15 @@ package object generic {
         val param = caseClass.parameters.head
         param.typeclass.imap(value => caseClass.rawConstruct(List(value)))(param.dereference)
       } else {
+        def recursiveShortNames(typeName: TypeName): Seq[String] = {
+          typeName.short +: typeName.typeArguments.flatMap(recursiveShortNames)
+        }
 
         Codec
           .record[A](
             name = caseClass.annotations
               .collectFirst { case AvroName(namespace) => namespace }
-              .getOrElse(caseClass.typeName.short),
+              .getOrElse(recursiveShortNames(caseClass.typeName).mkString("__")),
             namespace = caseClass.annotations
               .collectFirst { case AvroNamespace(namespace) => namespace }
               .getOrElse(caseClass.typeName.owner),
diff --git a/modules/generic/src/main/scala-3/vulcan/generic/package.scala b/modules/generic/src/main/scala-3/vulcan/generic/package.scala
index 90b538b5..53e7d7fb 100644
--- a/modules/generic/src/main/scala-3/vulcan/generic/package.scala
+++ b/modules/generic/src/main/scala-3/vulcan/generic/package.scala
@@ -28,12 +28,16 @@ package object generic {
   ) extends Derivation[Codec] {
     inline def derive[A](using Mirror.Of[A]): Codec[A] = derived[A]
 
-    final def join[A](caseClass: CaseClass[Codec, A]): Codec[A] = 
+    final def join[A](caseClass: CaseClass[Codec, A]): Codec[A] = {
+      def recursiveShortNames(typeInfo: TypeInfo): Seq[String] = {
+        typeInfo.short +: typeInfo.typeParams.toSeq.flatMap(recursiveShortNames)
+      }
+
       Codec
           .record[A](
             name = caseClass.annotations
               .collectFirst { case AvroName(namespace) => namespace }
-              .getOrElse(caseClass.typeInfo.short),
+              .getOrElse(recursiveShortNames(caseClass.typeInfo).mkString("__")),
             namespace = caseClass.annotations
               .collectFirst { case AvroNamespace(namespace) => namespace }
               .getOrElse(caseClass.typeInfo.owner),
@@ -68,6 +72,7 @@ package object generic {
               }
               .map(caseClass.rawConstruct(_))
           }
+    }
 
     final def split[A](sealedTrait: SealedTrait[Codec, A]): Codec.Aux[Any, A] = {
       Codec
diff --git a/modules/generic/src/test/scala/vulcan/generic/GenericDerivationCodecSpec.scala b/modules/generic/src/test/scala/vulcan/generic/GenericDerivationCodecSpec.scala
index b0505e24..952e794c 100644
--- a/modules/generic/src/test/scala/vulcan/generic/GenericDerivationCodecSpec.scala
+++ b/modules/generic/src/test/scala/vulcan/generic/GenericDerivationCodecSpec.scala
@@ -69,6 +69,18 @@ final class GenericDerivationCodecSpec extends CodecBase {
             }
           }
 
+          it("should append types classes in record name") {
+            assertSchemaIs[CaseClassTypeClass[String]] {
+              """{"type":"record","name":"CaseClassTypeClass__String","namespace":"vulcan.generic.examples","fields":[{"name":"value","type":["null","string"]}]}"""
+            }
+          }
+
+          it("should ignore type class names with annotation for record name") {
+            assertSchemaIs[CaseClassTypeClassAvroName[String]] {
+              """{"type":"record","name":"CaseClassOtherName","namespace":"vulcan.generic.examples","fields":[{"name":"value","type":["null","string"]}]}"""
+            }
+          }
+
         }
 
         describe("encode") {
diff --git a/modules/generic/src/test/scala/vulcan/generic/examples/CaseClassTypeClass.scala b/modules/generic/src/test/scala/vulcan/generic/examples/CaseClassTypeClass.scala
new file mode 100644
index 00000000..c93a34c7
--- /dev/null
+++ b/modules/generic/src/test/scala/vulcan/generic/examples/CaseClassTypeClass.scala
@@ -0,0 +1,10 @@
+package vulcan.generic.examples
+
+import vulcan.Codec
+import vulcan.generic._
+
+final case class CaseClassTypeClass[A](value: Option[A])
+
+object CaseClassTypeClass {
+  implicit val codecString: Codec[CaseClassTypeClass[String]] = Codec.derive
+}
diff --git a/modules/generic/src/test/scala/vulcan/generic/examples/CaseClassTypeClassAvroName.scala b/modules/generic/src/test/scala/vulcan/generic/examples/CaseClassTypeClassAvroName.scala
new file mode 100644
index 00000000..8e00f46f
--- /dev/null
+++ b/modules/generic/src/test/scala/vulcan/generic/examples/CaseClassTypeClassAvroName.scala
@@ -0,0 +1,11 @@
+package vulcan.generic.examples
+
+import vulcan.Codec
+import vulcan.generic._
+
+@AvroName("CaseClassOtherName")
+final case class CaseClassTypeClassAvroName[A](value: Option[A])
+
+object CaseClassTypeClassAvroName {
+  implicit val codecString: Codec[CaseClassTypeClassAvroName[String]] = Codec.derive
+}