src/libsyntax/util/lev_distance/tests.rs

use super::*;

#[test]
fn test_lev_distance() {
    use std::char::{from_u32, MAX};
    // Test bytelength agnosticity
    for c in (0..MAX as u32).filter_map(|i| from_u32(i)).map(|i| i.to_string()) {
        assert_eq!(lev_distance(&c[..], &c[..]), 0);
    }

    let a = "\nMäry häd ä little lämb\n\nLittle lämb\n";
    let b = "\nMary häd ä little lämb\n\nLittle lämb\n";
    let c = "Mary häd ä little lämb\n\nLittle lämb\n";
    assert_eq!(lev_distance(a, b), 1);
    assert_eq!(lev_distance(b, a), 1);
    assert_eq!(lev_distance(a, c), 2);
    assert_eq!(lev_distance(c, a), 2);
    assert_eq!(lev_distance(b, c), 1);
    assert_eq!(lev_distance(c, b), 1);
}

#[test]
fn test_find_best_match_for_name() {
    use crate::with_default_globals;
    with_default_globals(|| {
        let input = vec![Symbol::intern("aaab"), Symbol::intern("aaabc")];
        assert_eq!(
            find_best_match_for_name(input.iter(), "aaaa", None),
            Some(Symbol::intern("aaab"))
        );

        assert_eq!(find_best_match_for_name(input.iter(), "1111111111", None), None);

        let input = vec![Symbol::intern("aAAA")];
        assert_eq!(
            find_best_match_for_name(input.iter(), "AAAA", None),
            Some(Symbol::intern("aAAA"))
        );

        let input = vec![Symbol::intern("AAAA")];
        // Returns None because `lev_distance > max_dist / 3`
        assert_eq!(find_best_match_for_name(input.iter(), "aaaa", None), None);

        let input = vec![Symbol::intern("AAAA")];
        assert_eq!(
            find_best_match_for_name(input.iter(), "aaaa", Some(4)),
            Some(Symbol::intern("AAAA"))
        );
    })
}