'use strict';
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Object.defineProperty(exports, "__esModule", {
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value: true
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});
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exports.default = retry;
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var _noop = require('lodash/noop');
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var _noop2 = _interopRequireDefault(_noop);
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var _constant = require('lodash/constant');
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var _constant2 = _interopRequireDefault(_constant);
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var _wrapAsync = require('./internal/wrapAsync');
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var _wrapAsync2 = _interopRequireDefault(_wrapAsync);
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function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
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/**
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* Attempts to get a successful response from `task` no more than `times` times
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* before returning an error. If the task is successful, the `callback` will be
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* passed the result of the successful task. If all attempts fail, the callback
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* will be passed the error and result (if any) of the final attempt.
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*
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* @name retry
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* @static
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* @memberOf module:ControlFlow
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* @method
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* @category Control Flow
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* @see [async.retryable]{@link module:ControlFlow.retryable}
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* @param {Object|number} [opts = {times: 5, interval: 0}| 5] - Can be either an
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* object with `times` and `interval` or a number.
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* * `times` - The number of attempts to make before giving up. The default
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* is `5`.
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* * `interval` - The time to wait between retries, in milliseconds. The
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* default is `0`. The interval may also be specified as a function of the
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* retry count (see example).
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* * `errorFilter` - An optional synchronous function that is invoked on
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* erroneous result. If it returns `true` the retry attempts will continue;
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* if the function returns `false` the retry flow is aborted with the current
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* attempt's error and result being returned to the final callback.
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* Invoked with (err).
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* * If `opts` is a number, the number specifies the number of times to retry,
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* with the default interval of `0`.
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* @param {AsyncFunction} task - An async function to retry.
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* Invoked with (callback).
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* @param {Function} [callback] - An optional callback which is called when the
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* task has succeeded, or after the final failed attempt. It receives the `err`
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* and `result` arguments of the last attempt at completing the `task`. Invoked
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* with (err, results).
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*
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* @example
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*
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* // The `retry` function can be used as a stand-alone control flow by passing
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* // a callback, as shown below:
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*
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* // try calling apiMethod 3 times
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* async.retry(3, apiMethod, function(err, result) {
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* // do something with the result
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* });
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*
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* // try calling apiMethod 3 times, waiting 200 ms between each retry
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* async.retry({times: 3, interval: 200}, apiMethod, function(err, result) {
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* // do something with the result
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* });
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*
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* // try calling apiMethod 10 times with exponential backoff
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* // (i.e. intervals of 100, 200, 400, 800, 1600, ... milliseconds)
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* async.retry({
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* times: 10,
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* interval: function(retryCount) {
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* return 50 * Math.pow(2, retryCount);
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* }
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* }, apiMethod, function(err, result) {
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* // do something with the result
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* });
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*
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* // try calling apiMethod the default 5 times no delay between each retry
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* async.retry(apiMethod, function(err, result) {
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* // do something with the result
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* });
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*
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* // try calling apiMethod only when error condition satisfies, all other
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* // errors will abort the retry control flow and return to final callback
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* async.retry({
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* errorFilter: function(err) {
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* return err.message === 'Temporary error'; // only retry on a specific error
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* }
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* }, apiMethod, function(err, result) {
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* // do something with the result
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* });
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*
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* // to retry individual methods that are not as reliable within other
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* // control flow functions, use the `retryable` wrapper:
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* async.auto({
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* users: api.getUsers.bind(api),
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* payments: async.retryable(3, api.getPayments.bind(api))
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* }, function(err, results) {
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* // do something with the results
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* });
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*
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*/
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function retry(opts, task, callback) {
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var DEFAULT_TIMES = 5;
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var DEFAULT_INTERVAL = 0;
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var options = {
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times: DEFAULT_TIMES,
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intervalFunc: (0, _constant2.default)(DEFAULT_INTERVAL)
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};
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function parseTimes(acc, t) {
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if (typeof t === 'object') {
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acc.times = +t.times || DEFAULT_TIMES;
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acc.intervalFunc = typeof t.interval === 'function' ? t.interval : (0, _constant2.default)(+t.interval || DEFAULT_INTERVAL);
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acc.errorFilter = t.errorFilter;
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} else if (typeof t === 'number' || typeof t === 'string') {
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acc.times = +t || DEFAULT_TIMES;
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} else {
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throw new Error("Invalid arguments for async.retry");
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}
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}
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if (arguments.length < 3 && typeof opts === 'function') {
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callback = task || _noop2.default;
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task = opts;
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} else {
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parseTimes(options, opts);
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callback = callback || _noop2.default;
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}
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if (typeof task !== 'function') {
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throw new Error("Invalid arguments for async.retry");
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}
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var _task = (0, _wrapAsync2.default)(task);
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var attempt = 1;
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function retryAttempt() {
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_task(function (err) {
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if (err && attempt++ < options.times && (typeof options.errorFilter != 'function' || options.errorFilter(err))) {
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setTimeout(retryAttempt, options.intervalFunc(attempt));
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} else {
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callback.apply(null, arguments);
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}
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});
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}
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retryAttempt();
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}
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module.exports = exports['default'];
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