randomPasswordGenerator.js

const randomNumberGenerator = () => String.fromCharCode(parseInt(Math.random() * (57 - 49) + 49, 10));
const randomStringGenerator = () => String.fromCharCode(parseInt(Math.random() * (122 - 97) + 97, 10));

const randomPasswordGenerator = (len = 8, skip = ['l', '0', 'o', 'j']) => {
  let password = '';
  for (let i = 0; i < len; i++) {
    const gen = i < 2 ? randomStringGenerator() : randomNumberGenerator();
    if (skip.indexOf(gen) >= 0) {
      i--;
      continue;
    }

    password += gen;
  }

  return password;
};