def actual_path(path: str) -> str:
        """Get the actual path of `path`, including the correct case."""
        if path in _ACTUAL_PATH_CACHE:
            return _ACTUAL_PATH_CACHE[path]

        head, tail = os.path.split(path)
        if not tail:
            # This means head is the drive spec: normalize it.
            actpath = head.upper()
        elif not head:
            actpath = tail
        else:
            head = actual_path(head)
            if head in _ACTUAL_PATH_LIST_CACHE:
                files = _ACTUAL_PATH_LIST_CACHE[head]
            else:
                try:
                    files = os.listdir(head)
                except Exception:
                    # This will raise OSError, or this bizarre TypeError:
                    # https://bugs.python.org/issue1776160
                    files = []
                _ACTUAL_PATH_LIST_CACHE[head] = files
            normtail = os.path.normcase(tail)
            for f in files:
                if os.path.normcase(f) == normtail:
                    tail = f
                    break
            actpath = os.path.join(head, tail)
        _ACTUAL_PATH_CACHE[path] = actpath
        return actpath
Get the actual path of `path`, including the correct case.
coverage/files.py