HORIZON PROJECT

'use strict';

Object.defineProperty(exports, "__esModule", {

    value: true

});

exports.default = retry;

var _noop = require('lodash/noop');

var _noop2 = _interopRequireDefault(_noop);

var _constant = require('lodash/constant');

var _constant2 = _interopRequireDefault(_constant);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

/**

 * Attempts to get a successful response from `task` no more than `times` times

 * before returning an error. If the task is successful, the `callback` will be

 * passed the result of the successful task. If all attempts fail, the callback

 * will be passed the error and result (if any) of the final attempt.

 *

 * @name retry

 * @static

 * @memberOf module:ControlFlow

 * @method

 * @category Control Flow

 * @param {Object|number} [opts = {times: 5, interval: 0}| 5] - Can be either an

 * object with `times` and `interval` or a number.

 * * `times` - The number of attempts to make before giving up.  The default

 *   is `5`.

 * * `interval` - The time to wait between retries, in milliseconds.  The

 *   default is `0`. The interval may also be specified as a function of the

 *   retry count (see example).

 * * `errorFilter` - An optional synchronous function that is invoked on

 *   erroneous result. If it returns `true` the retry attempts will continue;

 *   if the function returns `false` the retry flow is aborted with the current

 *   attempt's error and result being returned to the final callback.

 *   Invoked with (err).

 * * If `opts` is a number, the number specifies the number of times to retry,

 *   with the default interval of `0`.

 * @param {Function} task - A function which receives two arguments: (1) a

 * `callback(err, result)` which must be called when finished, passing `err`

 * (which can be `null`) and the `result` of the function's execution, and (2)

 * a `results` object, containing the results of the previously executed

 * functions (if nested inside another control flow). Invoked with

 * (callback, results).

 * @param {Function} [callback] - An optional callback which is called when the

 * task has succeeded, or after the final failed attempt. It receives the `err`

 * and `result` arguments of the last attempt at completing the `task`. Invoked

 * with (err, results).

 * @example

 *

 * // The `retry` function can be used as a stand-alone control flow by passing

 * // a callback, as shown below:

 *

 * // try calling apiMethod 3 times

 * async.retry(3, apiMethod, function(err, result) {

 *     // do something with the result

 * });

 *

 * // try calling apiMethod 3 times, waiting 200 ms between each retry

 * async.retry({times: 3, interval: 200}, apiMethod, function(err, result) {

 *     // do something with the result

 * });

 *

 * // try calling apiMethod 10 times with exponential backoff

 * // (i.e. intervals of 100, 200, 400, 800, 1600, ... milliseconds)

 * async.retry({

 *   times: 10,

 *   interval: function(retryCount) {

 *     return 50 * Math.pow(2, retryCount);

 *   }

 * }, apiMethod, function(err, result) {

 *     // do something with the result

 * });

 *

 * // try calling apiMethod the default 5 times no delay between each retry

 * async.retry(apiMethod, function(err, result) {

 *     // do something with the result

 * });

 *

 * // try calling apiMethod only when error condition satisfies, all other

 * // errors will abort the retry control flow and return to final callback

 * async.retry({

 *   errorFilter: function(err) {

 *     return err.message === 'Temporary error'; // only retry on a specific error

 *   }

 * }, apiMethod, function(err, result) {

 *     // do something with the result

 * });

 *

 * // It can also be embedded within other control flow functions to retry

 * // individual methods that are not as reliable, like this:

 * async.auto({

 *     users: api.getUsers.bind(api),

 *     payments: async.retry(3, api.getPayments.bind(api))

 * }, function(err, results) {

 *     // do something with the results

 * });

 *

 */

function retry(opts, task, callback) {

    var DEFAULT_TIMES = 5;

    var DEFAULT_INTERVAL = 0;

    var options = {

        times: DEFAULT_TIMES,

        intervalFunc: (0, _constant2.default)(DEFAULT_INTERVAL)

    };

    function parseTimes(acc, t) {

        if (typeof t === 'object') {

            acc.times = +t.times || DEFAULT_TIMES;

            acc.intervalFunc = typeof t.interval === 'function' ? t.interval : (0, _constant2.default)(+t.interval || DEFAULT_INTERVAL);

            acc.errorFilter = t.errorFilter;

        } else if (typeof t === 'number' || typeof t === 'string') {

            acc.times = +t || DEFAULT_TIMES;

        } else {

            throw new Error("Invalid arguments for async.retry");

        }

    }

    if (arguments.length < 3 && typeof opts === 'function') {

        callback = task || _noop2.default;

        task = opts;

    } else {

        parseTimes(options, opts);

        callback = callback || _noop2.default;

    }

    if (typeof task !== 'function') {

        throw new Error("Invalid arguments for async.retry");

    }

    var attempt = 1;

    function retryAttempt() {

        task(function (err) {

            if (err && attempt++ < options.times && (typeof options.errorFilter != 'function' || options.errorFilter(err))) {

                setTimeout(retryAttempt, options.intervalFunc(attempt));

            } else {

                callback.apply(null, arguments);

            }

        });

    }

    retryAttempt();

}

module.exports = exports['default'];