Function needs_upgrade

atomic-remote/src/version.rs:18–31

Check if `current` version is less than `required` version. Performs a simple major.minor.patch numeric comparison. Missing parts default to 0 (e.g. `"1.2"` is treated as `"1.2.0"`). Returns `true` if `current < required` (upgrade needed). Returns `false` if `current >= required` or if either version string cannot be parsed — this avoids spurious warnings on dev or pre-release version strings.

(current: &str, required: &str)

/// cannot be parsed — this avoids spurious warnings on dev or pre-release
/// version strings.
pub fn needs_upgrade(current: &str, required: &str) -> bool {
    fn parse_version(v: &str) -> Option<(u32, u32, u32)> {
        let mut parts = v.trim().splitn(4, '.');
        let major = parts.next()?.parse::<u32>().ok()?;
        let minor = parts.next().unwrap_or("0").parse::<u32>().ok()?;
        let patch = parts.next().unwrap_or("0").parse::<u32>().ok()?;
        Some((major, minor, patch))
    }

    match (parse_version(current), parse_version(required)) {
        (Some(cur), Some(req)) => cur < req,
        _ => false,
    }
}

/// Check the `X-Atomic-Min-Version` response header and warn if the
/// current CLI version is older than the server's minimum requirement.