fast-check/lib/esm/check/arbitrary/helpers/ShrinkNumeric.js

Property based testing framework for JavaScript (like QuickCheck)

import { stream } from '../../../stream/Stream.js';
function shrinkNumericInternal(current, target, shrunkOnce, halvePos, halveNeg) {
    const realGap = (current - target);
    function* shrinkDecr() {
        const gap = shrunkOnce ? halvePos(realGap) : realGap;
        for (let toremove = gap; toremove > 0; toremove = halvePos(toremove)) {
            yield (current - toremove);
        }
    }
    function* shrinkIncr() {
        const gap = shrunkOnce ? halveNeg(realGap) : realGap;
        for (let toremove = gap; toremove < 0; toremove = halveNeg(toremove)) {
            yield (current - toremove);
        }
    }
    return realGap > 0 ? stream(shrinkDecr()) : stream(shrinkIncr());
}
function halveBigInt(n) {
    return n / BigInt(2);
}
function halvePosNumber(n) {
    return Math.floor(n / 2);
}
function halveNegNumber(n) {
    return Math.ceil(n / 2);
}
function shrinkNumeric(zero, min, max, current, shrunkOnce, halvePos, halveNeg) {
    if (min <= zero && max >= zero) {
        return shrinkNumericInternal(current, zero, shrunkOnce, halvePos, halveNeg);
    }
    return current < zero
        ? shrinkNumericInternal(current, max, shrunkOnce, halvePos, halveNeg)
        : shrinkNumericInternal(current, min, shrunkOnce, halvePos, halveNeg);
}
export function shrinkNumber(min, max, current, shrunkOnce) {
    return shrinkNumeric(0, min, max, current, shrunkOnce, halvePosNumber, halveNegNumber);
}
export function shrinkBigInt(min, max, current, shrunkOnce) {
    return shrinkNumeric(BigInt(0), min, max, current, shrunkOnce, halveBigInt, halveBigInt);
}