test.rs - mozsearch

use super::*;

use std::sync::atomic::AtomicUsize;

#[test]

fn same_range_first_consumers_return_correct_answer() {

    let find_op = |x: &i32| x % 2 == 0;

    let first_found = AtomicUsize::new(usize::max_value());

    let far_right_consumer = FindConsumer::new(&find_op, MatchPosition::Leftmost, &first_found);

    // We save a consumer that will be far to the right of the main consumer (and therefore not

    // sharing an index range with that consumer) for fullness testing

    let consumer = far_right_consumer.split_off_left();

    // split until we have an indivisible range

    let bits_in_usize = usize::min_value().count_zeros();

    for _ in 0..bits_in_usize {

        consumer.split_off_left();

    let reducer = consumer.to_reducer();

    // the left and right folders should now have the same range, having

    // exhausted the resolution of usize

    let left_folder = consumer.split_off_left().into_folder();

    let right_folder = consumer.into_folder();

    let left_folder = left_folder.consume(0).consume(1);

    assert_eq!(left_folder.boundary, right_folder.boundary);

    // expect not full even though a better match has been found because the

    // ranges are the same

    assert!(!right_folder.full());

    assert!(far_right_consumer.full());

    let right_folder = right_folder.consume(2).consume(3);

    assert_eq!(

        reducer.reduce(left_folder.complete(), right_folder.complete()),

        Some(0)

);

#[test]

fn same_range_last_consumers_return_correct_answer() {

    let find_op = |x: &i32| x % 2 == 0;

    let last_found = AtomicUsize::new(0);

    let consumer = FindConsumer::new(&find_op, MatchPosition::Rightmost, &last_found);

    // We save a consumer that will be far to the left of the main consumer (and therefore not

    // sharing an index range with that consumer) for fullness testing

    let far_left_consumer = consumer.split_off_left();

    // split until we have an indivisible range

    let bits_in_usize = usize::min_value().count_zeros();

    for _ in 0..bits_in_usize {

        consumer.split_off_left();

    let reducer = consumer.to_reducer();

    // due to the exact calculation in split_off_left, the very last consumer has a

    // range of width 2, so we use the second-to-last consumer instead to get

    // the same boundary on both folders

    let consumer = consumer.split_off_left();

    let left_folder = consumer.split_off_left().into_folder();

    let right_folder = consumer.into_folder();

    let right_folder = right_folder.consume(2).consume(3);

    assert_eq!(left_folder.boundary, right_folder.boundary);

    // expect not full even though a better match has been found because the

    // ranges are the same

    assert!(!left_folder.full());

    assert!(far_left_consumer.full());

    let left_folder = left_folder.consume(0).consume(1);

    assert_eq!(

        reducer.reduce(left_folder.complete(), right_folder.complete()),

        Some(2)

);

// These tests requires that a folder be assigned to an iterator with more than

// one element. We can't necessarily determine when that will happen for a given

// input to find_first/find_last, so we test the folder directly here instead.

#[test]

fn find_first_folder_does_not_clobber_first_found() {

    let best_found = AtomicUsize::new(usize::max_value());

    let f = FindFolder {

        find_op: &(|&_: &i32| -> bool { true }),

        boundary: 0,

        match_position: MatchPosition::Leftmost,

        best_found: &best_found,

        item: None,

};

    let f = f.consume(0_i32).consume(1_i32).consume(2_i32);

    assert!(f.full());

    assert_eq!(f.complete(), Some(0_i32));

#[test]

fn find_last_folder_yields_last_match() {

    let best_found = AtomicUsize::new(0);

    let f = FindFolder {

        find_op: &(|&_: &i32| -> bool { true }),

        boundary: 0,

        match_position: MatchPosition::Rightmost,

        best_found: &best_found,

        item: None,

};

    let f = f.consume(0_i32).consume(1_i32).consume(2_i32);

    assert_eq!(f.complete(), Some(2_i32));