Unit-testing.

[Thumuss]

The only thing tested is: regexes!!!!

#[cfg(test)]
mod tests {
    use super::*;
    #[test]
    fn regex() {
        let re = regex_package();
        assert!(re.is_match("@preview/package:2.0.1"));
        assert!(!re.is_match("@preview/package-:2.0.1"));
        assert!(!re.is_match("@local/package-A:2.0.1"));
        assert!(re.is_match("@local/package-a:2.0.1"));
        assert!(!re.is_match("@local/p:1..1"));
        assert!(re.is_match("@a/p:1.0.1"));
        assert!(!re.is_match("@/p:1.0.1"));
        assert!(!re.is_match("p:1.0.1"));
        assert!(!re.is_match("@a/p"));
    }
}

It's not sufficient at all