Function find_lib

tests/src/main.rs:265–305

Attempt find the rlib that matches `base`, if multiple rlibs are found then a clean build is required and `None` is returned.

(
    deps_target_dir: &Path,
    base: impl AsRef<Path>,
    dep_kind: DepKind,
    target: &str,
)

/// Attempt find the rlib that matches `base`, if multiple rlibs are found
/// then a clean build is required and `None` is returned.
fn find_lib(
    deps_target_dir: &Path,
    base: impl AsRef<Path>,
    dep_kind: DepKind,
    target: &str,
) -> Result<Option<PathBuf>> {
    let base = base.as_ref();
    let (expected_prefix, expected_extension) = dep_kind.prefix_and_extension();
    let expected_name = format!("{}{}", expected_prefix, base.display());

    let dir = deps_target_dir.join(dep_kind.target_dir_suffix(target));

    let paths = std::fs::read_dir(dir)?
        .filter_map(Result::ok)
        .map(|entry| entry.path())
        .filter(|path| {
            let name = {
                let name = path.file_stem();
                if name.is_none() {
                    return false;
                }
                name.unwrap()
            };

            let name_matches = name.to_str().unwrap().starts_with(&expected_name)
                && name.len() == expected_name.len() + 17   // we expect our name, '-', and then 16 hexadecimal digits
                && ends_with_dash_hash(name.to_str().unwrap());
            let extension_matches = path
                .extension()
                .map_or(false, |ext| ext == expected_extension);

            name_matches && extension_matches
        })
        .collect::<Vec<_>>();

    Ok(if paths.len() > 1 {
        None
    } else {
        paths.into_iter().next()
    })
}

/// Returns whether this string ends with a dash ('-'), followed by 16 lowercase hexadecimal characters
fn ends_with_dash_hash(s: &str) -> bool {