Additional test for named tuple custom extractor with mismatched type

Author: aherlihy

tests/neg/i23552.scala

@@ -0,0 +1,32 @@
+import NamedTuple.AnyNamedTuple
+
+sealed trait Z
+sealed trait S[n]
+
+type TupleList[+A, N] <: AnyNamedTuple =
+  N match
+    case Z => NamedTuple.Empty
+    case S[n] => (head: A, tail: TupleList[A, n])
+
+sealed trait Vect[+A, N]:
+  def ::[A1 >: A](a: A1): Vect[A1, S[N]] =
+    Vect.Cons(a, this)
+
+  def toTupleList: TupleList[A, N]
+
+object Vect:
+  case object Empty extends Vect[Nothing, Z]:
+    override def toTupleList: TupleList[Nothing, Z] = NamedTuple.Empty
+
+  case class Cons[A, N](head: A, tail: Vect[A, N]) extends Vect[A, S[N]]:
+    override def toTupleList: TupleList[A, S[N]] = (head, tail.toTupleList)
+
+object Foo:
+  def unapply[A, N](as: Vect[A, N]): Some[TupleList[A, N]] =
+    Some(as.toTupleList)
+
+@main
+def test: Unit =
+  (1 :: 2 :: 3 :: Vect.Empty) match
+    // missing parens around named tuple inside Foo causes compiler crash
+    case Foo(head = h, tail = t) => ??? // error