From d5edfd1e9eca8598960ae3ae2bb8faa7daeaa346 Mon Sep 17 00:00:00 2001
From: da-woods <dw-git@d-woods.co.uk>
Date: Wed, 14 Feb 2024 19:05:17 +0000
Subject: [PATCH] Test syntax error on comma-less tuple-style sequence patterns

Adds a test that length-1 tuple-style sequence patterns must end in a comma, since there isn't currently one.

Spotted while reviewing Cython's proposed implementation of the pattern matching syntax (https://github.com/cython/cython/pull/4897#discussion_r1489177169) where there was a bug my the reimplementation that wasn't caught against the CPython tests here.
---
 Lib/test/test_patma.py | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Lib/test/test_patma.py b/Lib/test/test_patma.py
index 298e78ccee3875..1bdab125dc6ef0 100644
--- a/Lib/test/test_patma.py
+++ b/Lib/test/test_patma.py
@@ -2957,6 +2957,14 @@ def test_invalid_syntax_3(self):
                 pass
         """)
 
+    def test_len1_tuple_sequence_pattern_comma(self):
+        # correct syntax would be `case(*x,):`
+        self.assert_syntax_error("""
+        match ...:
+            case (*x):
+                pass
+        """)
+
     def test_mapping_pattern_keys_may_only_match_literals_and_attribute_lookups(self):
         self.assert_syntax_error("""
         match ...: