handle constant folding with comments on multilines better

Author: asottile

pyupgrade/_token_helpers.py

@@ -369,6 +369,14 @@ def arg_str(tokens: list[Token], start: int, end: int) -> str:
     return tokens_to_src(tokens[start:end]).strip()
 
 
+def _arg_str_no_comment(tokens: list[Token], start: int, end: int) -> str:
+    arg_tokens = [
+        token for token in tokens[start:end]
+        if token.name != 'COMMENT'
+    ]
+    return tokens_to_src(arg_tokens).strip()
+
+
 def _arg_contains_newline(tokens: list[Token], start: int, end: int) -> bool:
     while tokens[start].name in {'NL', 'NEWLINE', UNIMPORTANT_WS}:
         start += 1
@@ -473,7 +481,7 @@ def replace_argument(
 def constant_fold_tuple(i: int, tokens: list[Token]) -> None:
     start = find_op(tokens, i, '(')
     func_args, end = parse_call_args(tokens, start)
-    arg_strs = [arg_str(tokens, *arg) for arg in func_args]
+    arg_strs = [_arg_str_no_comment(tokens, *arg) for arg in func_args]
 
     unique_args = tuple(dict.fromkeys(arg_strs))
 

tests/features/exceptions_test.py

@@ -225,6 +225,30 @@ def test_fix_exceptions_version_specific_noop(s, version):
 
             id='leave unrelated error names alone',
         ),
+        pytest.param(
+            'try: ...\n'
+            'except (\n'
+            '    BaseException,\n'
+            '    BaseException # b\n'
+            '): ...\n',
+
+            'try: ...\n'
+            'except BaseException: ...\n',
+
+            id='dedupe with comment.  see #932',
+        ),
+        pytest.param(
+            'try: ...\n'
+            'except (\n'
+            '    A, A,\n'
+            '    B  # b\n'
+            '): ...\n',
+
+            'try: ...\n'
+            'except (A, B): ...\n',
+
+            id='dedupe other exception, one contains comment.  see #932',
+        ),
     ),
 )
 def test_fix_exceptions(s, expected):