#[cfg(test)]
mod tests {
    use crate::multiplier::multiplier;
    use std::num::Wrapping;

    #[test]
    fn zero_times_one() {
        assert_eq!(multiplier(0, 1), 0 * 1);
    }

    #[test]
    fn four_times_three() {
        assert_eq!(multiplier(4, 3), 4 * 3);
    }

    #[test]
    fn one_times_one() {
        assert_eq!(multiplier(1, 1), 1 * 1);
    }

    #[test]
    fn random_numbers() {
        assert_eq!(multiplier(62_235, 12_756), 62_235 * 12_756);
        assert_eq!(multiplier(93_455, 4_756), 93_455 * 4_756);
        assert_eq!(multiplier(32_875, 23_655), 32_875 * 23_655);
        assert_eq!(multiplier(732_342, 796), 732_342 * 796);
    }

    #[test]
    fn overflow() {
        let big = Wrapping(3_245_532_214u32);
        assert_eq!(multiplier(3_245_532_214, 3_245_532_214), (big * big).0);
    }
}