From: da-woods <dw-git@d-woods.co.uk>
Date: Wed, 1 May 2024 08:33:28 +0000 (+0100)
Subject: Test syntax error on comma-less tuple-style sequence patterns (#115485)
X-Git-Tag: v3.13.0b1~188
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=21c09d9f8195433f34b72ddfa25dd1bda3019ed7;p=thirdparty%2FPython%2Fcpython.git

Test syntax error on comma-less tuple-style sequence patterns (#115485)

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.
---

diff --git a/Lib/test/test_patma.py b/Lib/test/test_patma.py
index 298e78ccee38..1bdab125dc6e 100644
--- a/Lib/test/test_patma.py
+++ b/Lib/test/test_patma.py
@@ -2957,6 +2957,14 @@ class TestSyntaxErrors(unittest.TestCase):
                 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 ...: