base64.js 579 Bytes
/* -*- Mode: js; js-indent-level: 2; -*- */
/*
 * Copyright 2011 Mozilla Foundation and contributors
 * Licensed under the New BSD license. See LICENSE or:
 * http://opensource.org/licenses/BSD-3-Clause
 */

const intToCharMap = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".split("");

/**
 * Encode an integer in the range of 0 to 63 to a single base 64 digit.
 */
exports.encode = function(number) {
  if (0 <= number && number < intToCharMap.length) {
    return intToCharMap[number];
  }
  throw new TypeError("Must be between 0 and 63: " + number);
};