reflectAll.js

import reflect from './reflect';
import isArray from 'lodash/isArray';
import _arrayMap from 'lodash/_arrayMap';
import forOwn from 'lodash/_baseForOwn';

/**
 * A helper function that wraps an array or an object of functions with reflect.
 *
 * @name reflectAll
 * @static
 * @memberOf module:Utils
 * @method
 * @see [async.reflect]{@link module:Utils.reflect}
 * @category Util
 * @param {Array} tasks - The array of functions to wrap in `async.reflect`.
 * @returns {Array} Returns an array of functions, each function wrapped in
 * `async.reflect`
 * @example
 *
 * let tasks = [
 *     function(callback) {
 *         setTimeout(function() {
 *             callback(null, 'one');
 *         }, 200);
 *     },
 *     function(callback) {
 *         // do some more stuff but error ...
 *         callback(new Error('bad stuff happened'));
 *     },
 *     function(callback) {
 *         setTimeout(function() {
 *             callback(null, 'two');
 *         }, 100);
 *     }
 * ];
 *
 * async.parallel(async.reflectAll(tasks),
 * // optional callback
 * function(err, results) {
 *     // values
 *     // results[0].value = 'one'
 *     // results[1].error = Error('bad stuff happened')
 *     // results[2].value = 'two'
 * });
 *
 * // an example using an object instead of an array
 * let tasks = {
 *     one: function(callback) {
 *         setTimeout(function() {
 *             callback(null, 'one');
 *         }, 200);
 *     },
 *     two: function(callback) {
 *         callback('two');
 *     },
 *     three: function(callback) {
 *         setTimeout(function() {
 *             callback(null, 'three');
 *         }, 100);
 *     }
 * };
 *
 * async.parallel(async.reflectAll(tasks),
 * // optional callback
 * function(err, results) {
 *     // values
 *     // results.one.value = 'one'
 *     // results.two.error = 'two'
 *     // results.three.value = 'three'
 * });
 */
export default function reflectAll(tasks) {
    var results;
    if (isArray(tasks)) {
        results = _arrayMap(tasks, reflect);
    } else {
        results = {};
        forOwn(tasks, function(task, key) {
            results[key] = reflect.call(this, task);
        });
    }
    return results;
}