review feedback

Author: slsyy

pre_commit_hooks/check_case_conflict.py

@@ -1,4 +1,5 @@
 import argparse
+import os.path
 from typing import Iterable
 from typing import Iterator
 from typing import Optional
@@ -15,7 +16,7 @@ def lower_set(iterable: Iterable[str]) -> Set[str]:
 
 def parents(file: str) -> Iterator[str]:
     while True:
-        file = file[:file.rfind('/')]
+        file = os.path.dirname(file)
         if not file:
             return
         yield file