source: frontend/node_modules/webpack/lib/util/ArrayHelpers.js

/*
        MIT License http://www.opensource.org/licenses/mit-license.php
        Author Tobias Koppers @sokra
*/

"use strict";

/**
 * Compare two arrays or strings by performing strict equality check for each value.
 * @template T
 * @param {ArrayLike<T>} a Array of values to be compared
 * @param {ArrayLike<T>} b Array of values to be compared
 * @returns {boolean} returns true if all the elements of passed arrays are strictly equal.
 */
module.exports.equals = (a, b) => {
        if (a.length !== b.length) return false;
        for (let i = 0; i < a.length; i++) {
                if (a[i] !== b[i]) return false;
        }
        return true;
};

/**
 * Partition an array by calling a predicate function on each value.
 * @template T
 * @param {T[]} arr Array of values to be partitioned
 * @param {(value: T) => boolean} fn Partition function which partitions based on truthiness of result.
 * @returns {[T[], T[]]} returns the values of `arr` partitioned into two new arrays based on fn predicate.
 */
module.exports.groupBy = (
        // eslint-disable-next-line default-param-last
        arr = [],
        fn
) =>
        arr.reduce(
                /**
                 * Handles the callback logic for this hook.
                 * @param {[T[], T[]]} groups An accumulator storing already partitioned values returned from previous call.
                 * @param {T} value The value of the current element
                 * @returns {[T[], T[]]} returns an array of partitioned groups accumulator resulting from calling a predicate on the current value.
                 */
                (groups, value) => {
                        groups[fn(value) ? 0 : 1].push(value);
                        return groups;
                },
                [[], []]
        );