mod tests {
    use super::*;

    #[test]
    fn range_lookup_handles_gaps() {
        let directory = tempfile::tempdir().unwrap();
        std::fs::write(
            directory.path().join("user-country-ipv4.csv"),
            "192.0.2.0,192.0.2.255,PL\n",
        )
        .unwrap();
        std::fs::write(
            directory.path().join("user-country-ipv6.csv"),
            "2001:db8::,2001:db8::ffff,PL\n",
        )
        .unwrap();
        let db = Database::load_format(directory.path(), DatabaseFormat::CsvPair).unwrap();
        assert_eq!(db.country("192.0.2.7".parse().unwrap()).as_deref(), Some("PL"));
        assert!(db.country("198.51.100.1".parse().unwrap()).is_none());
    }
}