git_policy_cli/lexical_path.rs
1//! What:
2//! Lexical path normalization, the way Node's `path.resolve` does it.
3//! Why:
4//! `git cli-git doctor` scans each hooks directory once, so one directory named two ways (`./hooks`, `hooks/`,
5//! `a/../hooks`) must compare equal without touching the file system.
6//!
7//! In TS you'd write (pseudocode):
8//! ```ts
9//! path.resolve(path);
10//! ```
11
12/// `Path`/`PathBuf` are borrowed/owned filesystem paths.
13use std::path::{Component, Path, PathBuf};
14
15/// What:
16/// Normalize a path lexically: drop `.`, fold `..` into the component before it, never above the root.
17/// Why:
18/// `PathBuf::join` keeps `.` and `..`, and a `..` above the root stays at the root, as Node clamps it.
19///
20/// In TS you'd write (pseudocode):
21/// ```ts
22/// path.resolve(path);
23/// ```
24pub fn normalized_path(path: &Path) -> PathBuf {
25 // `mut` lets the result grow and shrink as components arrive.
26 let mut result: PathBuf = PathBuf::new();
27 for component in path.components() {
28 match component {
29 Component::Prefix(_) | Component::RootDir => {
30 result.push(component.as_os_str());
31 }
32 Component::CurDir => {}
33 Component::ParentDir => {
34 let at_root: bool = result.parent().is_none();
35 if !at_root && result.file_name().is_some() {
36 result.pop();
37 }
38 }
39 Component::Normal(name) => {
40 result.push(name);
41 }
42 }
43 }
44 return result;
45}
46
47/// Normalization is controlled in the test module.
48#[cfg(test)]
49#[path = "lexical_path_tests.rs"]
50mod tests;