functionfoundry/fn/decodebase64.js

Pure function JavaScript library

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});

var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; };

exports.default = decodebase64;
// Copyright 2015 JC Fisher

function decodebase64(str) {

  if (typeof window !== 'undefined' && typeof atob !== 'undefined') {
    return window.atob(str);
  } else if (typeof module !== 'undefined' && module.exports) {
    return new Buffer(str, 'base64').toString();
  } else {
    var chars;

    var _ret = function () {
      var InvalidCharacterError = function InvalidCharacterError(message) {
        this.message = message;
      };

      var atob = function atob(input) {

        var str = String(input).replace(/=+$/, '');
        if (str.length % 4 == 1) {
          throw new InvalidCharacterError("'atob' failed: The string to be decoded is not correctly encoded.");
        }
        for (
        // initialize result and counters
        var bc = 0, bs, buffer, idx = 0, output = '';
        // get next character
        buffer = str.charAt(idx++);
        // character found in table? initialize bit storage and add its ascii value;
        ~buffer && (bs = bc % 4 ? bs * 64 + buffer : buffer,
        // and if not first of each 4 characters,
        // convert the first 8 bits to one ascii character
        bc++ % 4) ? output += String.fromCharCode(255 & bs >> (-2 * bc & 6)) : 0) {
          // try to find character in table (0-63, not found => -1)
          buffer = chars.indexOf(buffer);
        }
        return output;
      };

      chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';


      InvalidCharacterError.prototype = new Error();
      InvalidCharacterError.prototype.name = 'InvalidCharacterError';

      return {
        v: atob(str)
      };
    }();

    if ((typeof _ret === 'undefined' ? 'undefined' : _typeof(_ret)) === "object") return _ret.v;
  }
}
module.exports = exports['default'];