only process files in rescan, finally fix tests

src/filesystem.rs

@@ -113,6 +113,7 @@ fn _rescan_vault<T: AsRef<Path>>(
         .into_iter()
         .filter_map(|e| e.ok())
         .map(|e| fs::canonicalize(e.into_path()).unwrap())
+        .filter(|e| e.is_file())
         .filter(|e| !e.starts_with(&absolute_dir_path.join(UPEND_SUBDIR)))
         .collect();