randomize-any/dist/index.browser.cjs.cjs

A secure randomization utility library that provides various randomization functions, supporting both browser and Node.js environments.

'use strict';

Object.defineProperty(exports, '__esModule', { value: true });

/**
 * Randomize an element from an array
 * @param list array
 * @returns randomized element
 */
function randomizeAny(list) {
    const targetIndex = getSecureWeightedRandom(list.map(() => 1));
    return list[targetIndex];
}
/**
 * Randomize an integer
 * @param min minimum value
 * @param max maximum value
 * @returns randomized integer
 */
function randomizeInteger(min, max) {
    const list = generateArray(min, max);
    return randomizeAny(list);
}
/**
 * Randomize a float number
 * @param min minimum value
 * @param max maximum value
 * @returns randomized float number
 */
function randomizeFloat(min, max) {
    const list = generateArray(min, max, 0.01);
    return randomizeAny(list);
}
/**
 * Get a secure weighted random number
 * @param weights weight array
 * @returns randomized index
 */
function getSecureWeightedRandom(weights) {
    let sum = weights.reduce((acc, val) => acc + val, 0); // Calculate total weight
    // Generate a secure random number (range 0 ~ sum-1)
    let array = new Uint32Array(1);
    window.crypto.getRandomValues(array);
    let rand = array[0] / (0xFFFFFFFF + 1) * sum; // Normalize to [0, sum)
    // Iterate through weight array to find corresponding random index
    let cumulative = 0;
    for (let i = 0; i < weights.length; i++) {
        cumulative += weights[i];
        if (rand < cumulative) {
            return i;
        }
    }
    return getWeightedRandom(weights);
}
/**
 * Get a weighted random number
 * @param weights weight array
 * @returns randomized index
 */
function getWeightedRandom(weights) {
    const total = weights.reduce((acc, curr) => acc + curr, 0);
    const random = Math.random() * total;
    let sum = 0;
    for (let i = 0; i < weights.length; i++) {
        sum += weights[i];
        if (random < sum) {
            return i;
        }
    }
}
/**
 * Generate an array
 * @param min minimum value
 * @param max maximum value
 * @param step step size
 * @returns array
 */
function generateArray(min, max, step = 1) {
    const array = [];
    for (let i = min; i <= max; i += step) {
        array.push(i);
    }
    return array;
}

exports.getSecureWeightedRandom = getSecureWeightedRandom;
exports.randomizeAny = randomizeAny;
exports.randomizeFloat = randomizeFloat;
exports.randomizeInteger = randomizeInteger;