From c7c1a73b6e93e505b06736cbb6f8be79fdca32c1 Mon Sep 17 00:00:00 2001
From: Simon Peyton Jones <simon.peytonjones@gmail.com>
Date: Fri, 3 Mar 2023 08:21:22 +0000
Subject: Add test for T22793

---
 testsuite/tests/polykinds/T22793.hs     | 17 +++++++++++++
 testsuite/tests/polykinds/T22793.stderr | 44 +++++++++++++++++++++++++++++++++
 testsuite/tests/polykinds/all.T         |  1 +
 3 files changed, 62 insertions(+)
 create mode 100644 testsuite/tests/polykinds/T22793.hs
 create mode 100644 testsuite/tests/polykinds/T22793.stderr

diff --git a/testsuite/tests/polykinds/T22793.hs b/testsuite/tests/polykinds/T22793.hs
new file mode 100644
index 0000000000..3864748c49
--- /dev/null
+++ b/testsuite/tests/polykinds/T22793.hs
@@ -0,0 +1,17 @@
+{-# LANGUAGE PolyKinds #-}
+{-# LANGUAGE StandaloneKindSignatures #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+
+module T22793 where
+
+import Data.Kind
+
+type Foo :: forall k. k -> k -> Constraint
+
+class Foo s a
+
+bob :: forall {k1} {ks} {ka} q (p :: k1 -> q -> Type)
+              (f :: ka -> q) (s :: ks) (t :: ks)
+              (a :: ka) (b :: ka). Foo s a
+     => p a (f b) -> p s (f t)
+bob f = undefined
diff --git a/testsuite/tests/polykinds/T22793.stderr b/testsuite/tests/polykinds/T22793.stderr
new file mode 100644
index 0000000000..8082fa5be0
--- /dev/null
+++ b/testsuite/tests/polykinds/T22793.stderr
@@ -0,0 +1,44 @@
+
+T22793.hs:15:42: error: [GHC-25897]
+    • Couldn't match kind ‘ka’ with ‘k1’
+      Expected kind ‘ks’, but ‘a’ has kind ‘ka’
+      ‘ka’ is a rigid type variable bound by
+        the type signature for ‘bob’
+        at T22793.hs:13:26-27
+      ‘k1’ is a rigid type variable bound by
+        the type signature for ‘bob’
+        at T22793.hs:13:16-17
+    • In the second argument of ‘Foo’, namely ‘a’
+      In the type signature:
+        bob :: forall {k1}
+                      {ks}
+                      {ka}
+                      q
+                      (p :: k1 -> q -> Type)
+                      (f :: ka -> q)
+                      (s :: ks)
+                      (t :: ks)
+                      (a :: ka)
+                      (b :: ka). Foo s a => p a (f b) -> p s (f t)
+
+T22793.hs:16:11: error: [GHC-25897]
+    • Couldn't match kind ‘ks’ with ‘k1’
+      Expected kind ‘k1’, but ‘a’ has kind ‘ka’
+      ‘ks’ is a rigid type variable bound by
+        the type signature for ‘bob’
+        at T22793.hs:13:21-22
+      ‘k1’ is a rigid type variable bound by
+        the type signature for ‘bob’
+        at T22793.hs:13:16-17
+    • In the first argument of ‘p’, namely ‘a’
+      In the type signature:
+        bob :: forall {k1}
+                      {ks}
+                      {ka}
+                      q
+                      (p :: k1 -> q -> Type)
+                      (f :: ka -> q)
+                      (s :: ks)
+                      (t :: ks)
+                      (a :: ka)
+                      (b :: ka). Foo s a => p a (f b) -> p s (f t)
diff --git a/testsuite/tests/polykinds/all.T b/testsuite/tests/polykinds/all.T
index a73508858c..e16789136f 100644
--- a/testsuite/tests/polykinds/all.T
+++ b/testsuite/tests/polykinds/all.T
@@ -243,3 +243,4 @@ test('T22379a', normal, compile, [''])
 test('T22379b', normal, compile, [''])
 test('T22743', normal, compile_fail, [''])
 test('T22742', normal, compile_fail, [''])
+test('T22793', normal, compile_fail, [''])
-- 
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