1  'use strict';
 2  
 3  Object.defineProperty(exports, "__esModule", {
 4      value: true
 5  });
 6  
 7  var _eachSeries = require('./eachSeries');
 8  
 9  var _eachSeries2 = _interopRequireDefault(_eachSeries);
10  
11  var _wrapAsync = require('./internal/wrapAsync');
12  
13  var _wrapAsync2 = _interopRequireDefault(_wrapAsync);
14  
15  var _awaitify = require('./internal/awaitify');
16  
17  var _awaitify2 = _interopRequireDefault(_awaitify);
18  
19  function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
20  
21  /**
22   * It runs each task in series but stops whenever any of the functions were
23   * successful. If one of the tasks were successful, the `callback` will be
24   * passed the result of the successful task. If all tasks fail, the callback
25   * will be passed the error and result (if any) of the final attempt.
26   *
27   * @name tryEach
28   * @static
29   * @memberOf module:ControlFlow
30   * @method
31   * @category Control Flow
32   * @param {Array|Iterable|AsyncIterable|Object} tasks - A collection containing functions to
33   * run, each function is passed a `callback(err, result)` it must call on
34   * completion with an error `err` (which can be `null`) and an optional `result`
35   * value.
36   * @param {Function} [callback] - An optional callback which is called when one
37   * of the tasks has succeeded, or all have failed. It receives the `err` and
38   * `result` arguments of the last attempt at completing the `task`. Invoked with
39   * (err, results).
40   * @returns {Promise} a promise, if no callback is passed
41   * @example
42   * async.tryEach([
43   *     function getDataFromFirstWebsite(callback) {
44   *         // Try getting the data from the first website
45   *         callback(err, data);
46   *     },
47   *     function getDataFromSecondWebsite(callback) {
48   *         // First website failed,
49   *         // Try getting the data from the backup website
50   *         callback(err, data);
51   *     }
52   * ],
53   * // optional callback
54   * function(err, results) {
55   *     Now do something with the data.
56   * });
57   *
58   */
59  function tryEach(tasks, callback) {
60      var error = null;
61      var result;
62      return (0, _eachSeries2.default)(tasks, (task, taskCb) => {
63          (0, _wrapAsync2.default)(task)((err, ...args) => {
64              if (err === false) return taskCb(err);
65  
66              if (args.length < 2) {
67                  [result] = args;
68              } else {
69                  result = args;
70              }
71              error = err;
72              taskCb(err ? null : {});
73          });
74      }, () => callback(error, result));
75  }
76  
77  exports.default = (0, _awaitify2.default)(tryEach);
78  module.exports = exports['default'];