@mightyplow/jslib/object/fromArray.js

js helpers library

function _objectWithoutProperties(obj, keys) { var target = {}; for (var i in obj) { if (keys.indexOf(i) >= 0) continue; if (!Object.prototype.hasOwnProperty.call(obj, i)) continue; target[i] = obj[i]; } return target; }

import checkArray from '../array/_checkArray';

/**
 * Receives an array of objects and extracts an object with the given key as index. The key
 * must be a property of the array items. If the property is not found on the item, the item
 * is omitted.
 *
 * @memberOf object
 * @param {Object[]} array
 * @param {string} key
 * @param {boolean} keep - should the extracted prop be kept in the result object
 * @returns {*}
 */
var fromArray = function fromArray(array, key) {
    var keep = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : true;

    checkArray(array);

    if (!(typeof key === 'string')) {
        throw Error('key must be a string');
    }

    return array.reduce(function (object) {
        var item = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};

        var prop = item[key],
            rest = _objectWithoutProperties(item, [key]);

        if (!prop) {
            return object;
        }

        var value = item[key];
        object[value] = keep ? item : rest;

        return object;
    }, {});
};

export default fromArray;