@kitmi/utils/src/batchAsync_.js

A JavaScript utility library for both server and browser

import isPlainObject from './isPlainObject';

/**
 * Walk through each entry of an array of an object parallelly, faster than eachAsync_
 * @alias collection.batchAsync_
 * @async
 * @param {Array|Object} obj
 * @param {asyncIterator} iterator
 * @returns {Promise.<Array|Object>}
 */
async function batchAsync_(obj, iterator) {
    if (Array.isArray(obj)) {
        const r = [];

        let l = obj.length;
        for (let i = 0; i < l; i++) {
            r.push(iterator(obj[i], i, obj));
        }

        return Promise.all(r);
    }

    if (isPlainObject(obj)) {
        const keys = [];
        const values = [];

        for (let k in obj) {
            if (Object.prototype.hasOwnProperty.call(obj, k)) {
                keys.push(k);
                values.push(iterator(obj[k], k, obj));
            }
        }

        const result = await Promise.all(values);
        return keys.reduce((r, k, i) => {
            r[k] = result[i];
            return r;
        }, {});
    }

    throw new Error('Invalid argument!');
}

export default batchAsync_;