1pub(crate) fn parent_dir(path: &str) -> &str {
5 path.rsplit_once('/').map_or("", |(parent, _)| parent)
6}
7
8pub(crate) fn parent_dir_for_lookup(path: &str) -> Option<&str> {
9 if path.is_empty() {
10 return None;
11 }
12
13 path.rsplit_once('/').map(|(parent, _)| parent).or(Some(""))
14}
15
16#[cfg(test)]
17mod tests {
18 use super::{parent_dir, parent_dir_for_lookup};
19
20 #[test]
21 fn parent_dir_handles_top_level_paths() {
22 assert_eq!(parent_dir("package.json"), "");
23 assert_eq!(parent_dir("packages/app/package.json"), "packages/app");
24 }
25
26 #[test]
27 fn parent_dir_for_lookup_walks_up_to_empty_root() {
28 assert_eq!(parent_dir_for_lookup("packages/app"), Some("packages"));
29 assert_eq!(parent_dir_for_lookup("packages"), Some(""));
30 assert_eq!(parent_dir_for_lookup(""), None);
31 }
32}