rusty-numbers/tests/fractions.rs

#![cfg_attr(tarpaulin, skip)]

use rusty_numbers::frac;
use rusty_numbers::rational::Frac;

#[test]
fn mul_test() {
    let frac1 = frac!(1 / 3u8);
    let frac2 = frac!(2u8 / 3);

    let expected = frac!(2u8 / 9);

    assert_eq!(frac1 * frac2, expected);

    assert_eq!(frac!(0), frac!(0) * frac!(5 / 8));
}

#[test]
fn div_test() {
    assert_eq!(frac!(1), frac!(1 / 3) / frac!(1 / 3));
    assert_eq!(frac!(1 / 9), frac!(1 / 3) / frac!(3));
}

#[test]
fn add_test() {
    assert_eq!(frac!(5 / 8), frac!(5 / 8) + frac!(0));
    assert_eq!(frac!(5 / 6), frac!(1 / 3) + frac!(1 / 2), "1/3 + 1/2");
    assert_eq!(frac!(1 / 3), frac!(2 / 3) + -frac!(1 / 3), "2/3 + -1/3");
}

#[test]
fn sub_test() {
    assert_eq!(frac!(5 / 8), frac!(5 / 8) - frac!(0));
    assert_eq!(frac!(1 / 6), frac!(1 / 2) - frac!(1 / 3), "1/2 - 1/3");
}

#[test]
fn cmp_test() {
    assert!(frac!(1 / 2) <= frac!(1 / 2));
    assert!(frac!(0) < frac!(1));
    assert!(-frac!(5 / 3) < frac!(1 / 10_000));
    assert!(frac!(1 / 10_000) > -frac!(10));
    assert!(frac!(1 / 3) < frac!(1 / 2));
    assert_eq!(frac!(1 / 2), frac!(3 / 6));
}

#[test]
fn negative_fractions() {
    assert_eq!(-frac!(1 / 3), -frac!(2 / 3) + frac!(1 / 3), "-2/3 + 1/3");
    assert_eq!(frac!(1), frac!(1 / 3) - -frac!(2 / 3), "1/3 - -2/3");
    assert_eq!(-frac!(1), -frac!(2 / 3) - frac!(1 / 3), "-2/3 - +1/3");
    assert_eq!(-frac!(1), -frac!(2 / 3) + -frac!(1 / 3), "-2/3 + -1/3");
}

#[test]
fn negative_mul_div() {
    assert_eq!(-frac!(1 / 12), -frac!(1 / 3) * frac!(1 / 4));
    assert_eq!(-frac!(1 / 12), frac!(1 / 3) * -frac!(1 / 4));
    assert_eq!(frac!(1 / 12), -frac!(1 / 3) * -frac!(1 / 4));
}

#[test]
#[should_panic(expected = "Fraction can not have a zero denominator")]
fn zero_denom() {
    frac!(1 / 0);
}

#[test]
fn fraction_reducing() {
    assert_eq!(frac!(1u8/2), Frac::new_unreduced(48u8, 96u8).reduce());
}

#[test]
fn op_assign() {
    // Addition
    let mut quart = frac!(1 / 4);
    quart += frac!(1 / 4);
    assert_eq!(frac!(1 / 2), quart);

    // Subtraction
    let mut half = frac!(1 / 2);
    half -= frac!(1 / 4);
    assert_eq!(frac!(1 / 4), half);

    // Multiplication
    let mut half = frac!(1 / 2);
    half *= frac!(1 / 2);
    assert_eq!(frac!(1 / 4), half);

    // Division
    let mut quart = frac!(1 / 4);
    quart /= frac!(4);
    assert_eq!(frac!(1 / 16), quart);
}