JAVASCRIPT   8

whilst.js

Guest on 21st May 2021 06:48:08 AM

  1. 'use strict';
  2.  
  3. Object.defineProperty(exports, "__esModule", {
  4.     value: true
  5. });
  6. exports.default = whilst;
  7.  
  8. var _noop = require('lodash/noop');
  9.  
  10. var _noop2 = _interopRequireDefault(_noop);
  11.  
  12. var _slice = require('./internal/slice');
  13.  
  14. var _slice2 = _interopRequireDefault(_slice);
  15.  
  16. var _onlyOnce = require('./internal/onlyOnce');
  17.  
  18. var _onlyOnce2 = _interopRequireDefault(_onlyOnce);
  19.  
  20. var _wrapAsync = require('./internal/wrapAsync');
  21.  
  22. var _wrapAsync2 = _interopRequireDefault(_wrapAsync);
  23.  
  24. function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
  25.  
  26. /**
  27.  * Repeatedly call `iteratee`, while `test` returns `true`. Calls `callback` when
  28.  * stopped, or an error occurs.
  29.  *
  30.  * @name whilst
  31.  * @static
  32.  * @memberOf module:ControlFlow
  33.  * @method
  34.  * @category Control Flow
  35.  * @param {Function} test - synchronous truth test to perform before each
  36.  * execution of `iteratee`. Invoked with ().
  37.  * @param {AsyncFunction} iteratee - An async function which is called each time
  38.  * `test` passes. Invoked with (callback).
  39.  * @param {Function} [callback] - A callback which is called after the test
  40.  * function has failed and repeated execution of `iteratee` has stopped. `callback`
  41.  * will be passed an error and any arguments passed to the final `iteratee`'s
  42.  * callback. Invoked with (err, [results]);
  43.  * @returns undefined
  44.  * @example
  45.  *
  46.  * var count = 0;
  47.  * async.whilst(
  48.  *     function() { return count < 5; },
  49.  *     function(callback) {
  50.  *         count++;
  51.  *         setTimeout(function() {
  52.  *             callback(null, count);
  53.  *         }, 1000);
  54.  *     },
  55.  *     function (err, n) {
  56.  *         // 5 seconds have passed, n = 5
  57.  *     }
  58.  * );
  59.  */
  60. function whilst(test, iteratee, callback) {
  61.     callback = (0, _onlyOnce2.default)(callback || _noop2.default);
  62.     var _iteratee = (0, _wrapAsync2.default)(iteratee);
  63.     if (!test()) return callback(null);
  64.     var next = function (err /*, ...args*/) {
  65.         if (err) return callback(err);
  66.         if (test()) return _iteratee(next);
  67.         var args = (0, _slice2.default)(arguments, 1);
  68.         callback.apply(null, [null].concat(args));
  69.     };
  70.     _iteratee(next);
  71. }
  72. module.exports = exports['default'];

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