在 Linux 和 macOS 系统上，
On Linux and macOS systems,
fs.watch() resolves the path to an inode and
watches the inode. If the watched path is deleted and recreated, it is assigned
a new inode. The watch will emit an event for the delete but will continue
watching the original inode. Events for the new inode will not be emitted.
This is expected behavior.
AIX files retain the same inode for the lifetime of a file. Saving and closing a watched file on AIX will result in two notifications (one for adding new content, and one for truncation).