Password generator function

clientScript.js

function onLoad() {
    var generatePassword = new GlideAjax('x_fstfs_fj_cmp.TfSCMPClientUtils');
  
    function setPassword (password) {
      g_form.setValue('AWS_Windows_UserPassword', password);
    }

    generatePassword.addParam('sysparm_name', 'generateRandomPassword');
    generatePassword.getXMLAnswer(setPassword);
}

generateRandomPassword.js

/**
 * Generates random password. Uses ES5 syntax that can be used in ServiceNow.
 * @param {number} length - length of the password, default 20. Min 8, max 100
 * @param {boolean} noSpecials - truthie if you don't want specil characters like !?-_&%
 * @param {boolean} noNumbers - truthie if you don't want numbers
 * @param {boolean} noCapitals - truthie if you don't want capital letters
 * @param {boolean} noForceComplexity - truthie to disable enforcing all char types in password
 * @return {string} randomly generated password string
 */
function generateRandomPassword(length, noSpecials, noNumbers, noCapitals, noForceComplexity) {
  var defaultLength = 20;
  var minPasswordLength = 8;
  var maxPasswordLength = 100;
  var lower = 'abcdefghijklmnopqrstuvwxyz';
  var numbers = '0123456789';
  var specials = '!?_&%*-'; // do not add - to middle since it will break the regex rule!
  var chars = [
    { chars: lower, disabled: false },
    { chars: lower.toUpperCase(), disabled: noCapitals },
    { chars: numbers, disabled: noNumbers },
    { chars: specials, disabled: noSpecials },
  ];
  var allCharacters = chars
    .map(function (i) {
      if (!i.disabled) return i.chars;
    })
    .join('');
  var validatedLength;
  var outputArray;
  var password;

  function validate(n) {
    return !(isNaN(n) || n < minPasswordLength || n > maxPasswordLength);
  }

  function getRandomCharacter() {
    return allCharacters.charAt(
      Math.floor(Math.random() * allCharacters.length);
    );
  }

  function generatePassword(arr) {
    return arr
      .map(function (i) {
        return getRandomCharacter();
      })
      .join('');
  }

  function validatePassword() {
    var regexRule;
    return chars.map(function (i) {
      if (i.disabled) return true;

      regexRule = new RegExp('[' + i.chars + ']');
      return regexRule.test(password);
    }).every(function(i){return i});
  }

  validatedLength = validate(length) ? parseInt(length, 10) : defaultLength;
  outputArray = Array.apply(null, Array(validatedLength));

  do {
    password = generatePassword(outputArray);
  }
  while (!noForceComplexity && !validatePassword(password));

  return password;
}

console.log(generateRandomPassword(22));

/*
as default value in catalog item (does not work in cmp portal, use client script instead):
javascript:new x_fstfs_fj_cmp.TfSCMPClientUtils().generateRandomPassword();
*/