mod short_hex {
    #[test]
    fn display_entire_range_sha1() {
        let id_hex = "0123456789abcdef123456789abcdef123456789";
        let id = git_hash::ObjectId::from_hex(id_hex.as_bytes()).expect("valid input");
        for len in 0..=40 {
            assert_eq!(id.to_hex(len).to_string(), id_hex[..len]);
        }
        assert_eq!(
            id.to_hex(120).to_string(),
            id_hex,
            "values that are too long are truncated"
        );
    }
}