From c406aceea233560330001e9a64bc0f35723962cf Mon Sep 17 00:00:00 2001
From: Dale Wijnand <dale.wijnand@gmail.com>
Date: Tue, 11 Oct 2022 14:00:01 +0100
Subject: [PATCH] Add fixed GADT exhaustivity test cases

---
 tests/pos/i7424.scala  | 12 ++++++++++++
 tests/pos/i7424b.scala | 12 ++++++++++++
 tests/pos/i7424c.scala |  8 ++++++++
 3 files changed, 32 insertions(+)
 create mode 100644 tests/pos/i7424.scala
 create mode 100644 tests/pos/i7424b.scala
 create mode 100644 tests/pos/i7424c.scala

diff --git a/tests/pos/i7424.scala b/tests/pos/i7424.scala
new file mode 100644
index 000000000000..33987610519e
--- /dev/null
+++ b/tests/pos/i7424.scala
@@ -0,0 +1,12 @@
+// scalac: -Werror
+object GADT {
+  import =:=._
+
+  enum =:=[A, B] {
+    case Refl[C]() extends (C =:= C)
+  }
+
+  def unwrap[A,B](opt: Option[A])(using ev: A =:= Option[B]): Option[B] = ev match {
+    case Refl() => opt.flatMap(identity[Option[B]])
+  }
+}
diff --git a/tests/pos/i7424b.scala b/tests/pos/i7424b.scala
new file mode 100644
index 000000000000..5fdf878a2330
--- /dev/null
+++ b/tests/pos/i7424b.scala
@@ -0,0 +1,12 @@
+// scalac: -Werror
+object GADT {
+  import =:=._
+
+  enum =:=[A, B] {
+    case Refl[C]() extends (C =:= C)
+  }
+
+  def unwrap[A,B](opt: Option[A])(using ev: A =:= Option[B]): Option[B] = ev match {
+    case _: Refl[?] => opt.flatMap(identity[Option[B]])
+  }
+}
diff --git a/tests/pos/i7424c.scala b/tests/pos/i7424c.scala
new file mode 100644
index 000000000000..e27b17964253
--- /dev/null
+++ b/tests/pos/i7424c.scala
@@ -0,0 +1,8 @@
+// scalac: -Werror
+object Main extends App:
+   enum Extends[A, B]:
+     case Ev[B, A <: B]() extends (A Extends B)
+
+     def cast(a: A): B = this match {
+       case Extends.Ev() => a
+     }