From f2d3d4e1546709d73ec19222e06f3630bc2eb55b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20=C5=A0pan=C4=9Bl?=
 <OndrejSpanel@users.noreply.github.com>
Date: Thu, 1 Sep 2022 15:52:22 +0200
Subject: [PATCH] Invert case class detection logic

---
 .../softwaremill/quicklens/QuicklensMacros.scala  | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/quicklens/src/main/scala-3/com/softwaremill/quicklens/QuicklensMacros.scala b/quicklens/src/main/scala-3/com/softwaremill/quicklens/QuicklensMacros.scala
index 19ed879..e5fafe1 100644
--- a/quicklens/src/main/scala-3/com/softwaremill/quicklens/QuicklensMacros.scala
+++ b/quicklens/src/main/scala-3/com/softwaremill/quicklens/QuicklensMacros.scala
@@ -161,7 +161,9 @@ object QuicklensMacros {
         fields: Seq[(PathSymbol.Field, Seq[PathTree])]
     ): Term = {
       val objSymbol = obj.tpe.typeSymbol
-      if objSymbol.flags.is(Flags.Case) then {
+      if !(objSymbol.flags.is(Flags.Enum) ||
+        (objSymbol.flags.is(Flags.Sealed) && (objSymbol.flags.is(Flags.Trait) || objSymbol.flags.is(Flags.Abstract))))
+      then {
         val copy = termMethodByNameUnsafe(obj, "copy")
         val argsMap: Map[Int, Term] = fields.map { (field, trees) =>
           val (fieldMethod, idx) = termAccessorMethodByNameUnsafe(obj, field.name)
@@ -185,11 +187,9 @@ object QuicklensMacros {
           case AppliedType(_, typeParams) => Apply(TypeApply(Select(obj, copy), typeParams.map(Inferred(_))), args)
           case _                          => Apply(Select(obj, copy), args)
         }
-      } else if objSymbol.flags.is(Flags.Enum) ||
-        (objSymbol.flags.is(Flags.Sealed) && (objSymbol.flags.is(Flags.Trait) || objSymbol.flags.is(Flags.Abstract)))
-      then {
+      } else {
         // if the source is a sealed trait / sealed abstract class / enum, generating a if-then-else with a .copy for each child (implementing case class)
-        val cases = obj.tpe.typeSymbol.children.map { child =>
+        val cases = objSymbol.children.map { child =>
           val subtype = TypeIdent(child)
           val bind = Symbol.newBind(owner, "c", Flags.EmptyFlags, subtype.tpe)
           CaseDef(Bind(bind, Typed(Ref(bind), subtype)), None, caseClassCopy(owner, mod, Ref(bind), fields))
@@ -201,7 +201,7 @@ object QuicklensMacros {
         ...
         else throw new IllegalStateException()
          */
-        val ifThens = obj.tpe.typeSymbol.children.map { child =>
+        val ifThens = objSymbol.children.map { child =>
           val ifCond = TypeApply(Select.unique(obj, "isInstanceOf"), List(TypeIdent(child)))
 
           val ifThen = ValDef.let(owner, TypeApply(Select.unique(obj, "asInstanceOf"), List(TypeIdent(child)))) {
@@ -216,8 +216,7 @@ object QuicklensMacros {
         ifThens.foldRight(elseThrow) { case ((ifCond, ifThen), ifElse) =>
           If(ifCond, ifThen, ifElse)
         }
-      } else
-        report.throwError(s"Unsupported source object: must be a case class or sealed trait, but got: $objSymbol")
+      }
     }
 
     def applyFunctionDelegate(