Add an example of derive keyword usage for a complex generic type

Author: plokhotnyuk

jsoniter-scala-macros/shared/src/main/scala-3/com/github/plokhotnyuk/jsoniter_scala/macros/JsonCodecMaker.scala

@@ -1786,7 +1786,7 @@ object JsonCodecMaker {
           tpe match
             case ConstantType(c) => Literal(c).asExprOf[T]
             case _ => cannotFindValueCodecError(tpe)
-        } else if (isEnumOrModuleValue(tpe)) Ref(tpe.termSymbol).asExprOf[T]
+        } else if (isEnumOrModuleValue(tpe)) Ref(tpe.termSymbol).asExprOf[T] // FIXME: add support of non top-level defiend enums
         else if (isValueClass(tpe)) {
           val tpe1 = valueClassValueType(tpe)
           tpe1.asType match
@@ -2632,7 +2632,7 @@ object JsonCodecMaker {
             if ($in.isNextToken('{')) {
               $in.rollbackToken()
               $in.skip()
-              ${if (tpe =:= TypeRepr.of[None.type]) '{ None }.asExprOf[T] else Ref(tpe.termSymbol).asExprOf[T]}
+              ${if (tpe =:= TypeRepr.of[None.type]) '{ None }.asExprOf[T] else Ref(tpe.termSymbol).asExprOf[T]}  // FIXME: add support of non top-level defiend enums
             } else $in.readNullOrTokenError($default, '{')
           }
         } else if (isSealedClass(tpe)) withDecoderFor(methodKey, default, in) { (in, default) =>

jsoniter-scala-macros/shared/src/test/scala-3/com/github/plokhotnyuk/jsoniter_scala/macros/JsonCodecMakerNewKeywordSpec.scala

@@ -84,5 +84,17 @@ class JsonCodecMakerNewKeywordSpec extends VerifyingSpec {
         verifySerDeser(summon[JsonValueCodec[TestEnum]], TestEnum.Value2("VVV"), """{"hint":"Value2","str":"VVV"}""")
       }
     }
+    "serialize and deserialize a complex generic types defined with `derives` keyword and a custom compile-time configurations" in {
+      verifySerDeser(make[LinkedList[Int]](CodecMakerConfig.withAllowRecursiveTypes(true)),
+        LinkedList.Node2[Int](2, LinkedList.Node[Int](1, LinkedList.End)),
+        """{"type":"Node2","value":2,"next":{"value":1,"next":{"type":"End"}}}""")
+    }
   }
-}
+}
+
+inline given CodecMakerConfig = CodecMakerConfig.withAllowRecursiveTypes(true)
+
+enum LinkedList[+T] derives ConfiguredJsonValueCodec: // Borrowed from https://github.com/com-lihaoyi/upickle/pull/607
+  case End
+  case Node(value: T, next: LinkedList[T])
+  case Node2(value: T, next: Node[T])