python.gram: stricter rule for trailing comma in import (#38)

cf python/cpython@b2f68b1
we-like-parsers · Aug 19, 2021 · d130038 · d130038
1 parent a806a6a
commit d130038
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Showing 2 changed files with 2 additions and 1 deletion.
diff --git a/data/python.gram b/data/python.gram
@@ -1753,7 +1753,7 @@ invalid_group[NoReturn]:
         self.raise_syntax_error_known_location("cannot use double starred expression here", a)
      }
 invalid_import_from_targets[NoReturn]:
-    | import_from_as_names ',' {
+    | import_from_as_names ',' NEWLINE {
         self.raise_syntax_error("trailing comma not allowed without surrounding parentheses")
      }
 

diff --git a/tests/python_parser/test_syntax_error_handling.py b/tests/python_parser/test_syntax_error_handling.py
@@ -289,6 +289,7 @@ def test_invalid_group(python_parse_file, python_parse_str, tmp_path, source, me
     "source, message",
     [
         ("from a import b,", "trailing comma not allowed without surrounding parentheses"),
+        ("from a import b, and 3", "invalid syntax"),
         ("from a import raise", "invalid syntax"),
     ],
 )