insistence/dist/insistence.js

Insistently runs a callback and only resolves the promise when its result is truthy.

/*!
 * insistence v0.2.0
 * (c) 2018-present Vitor Luiz Cavalcanti <vitorluizc@outlook.com> (https://vitorluizc.github.io)
 * Released under the MIT License.
 */
(function (global, factory) {
    typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
    typeof define === 'function' && define.amd ? define(factory) :
    (global.insistence = factory());
}(this, (function () { 'use strict';

    /**
     * Returns a Promise which is resolved after delay.
     * @param time Delay time in milliseconds.
     */
    function delay(time) {
      return new Promise(function (resolve) { return setTimeout(resolve, time); });
    }
    /**
     * Returns check result or `false` if an error is thrown.
     * @param λ A function that checks if it don't need to keep insisting.
     */


    function getSuccess(λ) {
      try {
        return λ();
      } catch (_) {
        return false;
      }
    }
    /**
     * Insistently runs a callback and only resolves the promise when its result is truthy.
     * @param λ A function that checks if it don't need to keep insisting.
     * @param time Time in millisencons to insist again.
     */


    function Insistence(λ, time) {
      if ( time === void 0 ) time = 200;

      return new Promise(function (resolve) {
        var insist = function () {
          var success = getSuccess(λ);
          return Promise.resolve(success).then(function (success) {
            if (!success) { throw new Error('Success not achieved. Keep insisting.'); }
            resolve();
          }).catch(function () { return delay(time).then(insist); });
        };

        return insist();
      });
    }

    return Insistence;

})));