cargo_util/
registry.rs

1/// Make a path to a dependency, which aligns to
2///
3/// - [index from of Cargo's index on filesystem][1], and
4/// - [index from Crates.io][2].
5///
6/// <div class="warning">
7///
8/// Note: For index files, `dep_name` must have had `to_lowercase` called on it.
9///
10/// </div>
11///
12/// [1]: https://docs.rs/cargo/latest/cargo/sources/registry/index.html#the-format-of-the-index
13/// [2]: https://github.com/rust-lang/crates.io-index
14pub fn make_dep_path(dep_name: &str, prefix_only: bool) -> String {
15    let (slash, name) = if prefix_only {
16        ("", "")
17    } else {
18        ("/", dep_name)
19    };
20    match dep_name.len() {
21        1 => format!("1{}{}", slash, name),
22        2 => format!("2{}{}", slash, name),
23        3 => format!("3/{}{}{}", &dep_name[..1], slash, name),
24        _ => format!("{}/{}{}{}", &dep_name[0..2], &dep_name[2..4], slash, name),
25    }
26}
27
28#[cfg(test)]
29mod tests {
30    use super::make_dep_path;
31
32    #[test]
33    fn prefix_only() {
34        assert_eq!(make_dep_path("a", true), "1");
35        assert_eq!(make_dep_path("ab", true), "2");
36        assert_eq!(make_dep_path("abc", true), "3/a");
37        assert_eq!(make_dep_path("Abc", true), "3/A");
38        assert_eq!(make_dep_path("AbCd", true), "Ab/Cd");
39        assert_eq!(make_dep_path("aBcDe", true), "aB/cD");
40    }
41
42    #[test]
43    fn full() {
44        assert_eq!(make_dep_path("a", false), "1/a");
45        assert_eq!(make_dep_path("ab", false), "2/ab");
46        assert_eq!(make_dep_path("abc", false), "3/a/abc");
47        assert_eq!(make_dep_path("Abc", false), "3/A/Abc");
48        assert_eq!(make_dep_path("AbCd", false), "Ab/Cd/AbCd");
49        assert_eq!(make_dep_path("aBcDe", false), "aB/cD/aBcDe");
50    }
51}