Generate a random password in JavaScript; based on your char selection

randomPassword.js

const getRandomCharsFromString = (charset, length) =>
  charset.split('')
    .sort(() => Math.random() - 0.5)
    .slice(0, length)
    .join('')

export const generateRandomPassword = () => (
  [
    getRandomCharsFromString('0123456789', 4),
    getRandomCharsFromString('ABCDEFGHIJKLMNOPQRSTUVWXYZ', 6),
    getRandomCharsFromString('abcdefghijklmnopqrstuvwxyz', 6),
    getRandomCharsFromString('.,<>;:?&*!@#$%', 4),
  ]
    .join('')
    .split('')
    .sort(() => Math.random() - 0.5)
    .join('')
)

randomPassword.ts

const getRandomCharsFromString = (charset: string, length: number) =>
  charset.split('')
    .sort(() => Math.random() - 0.5)
    .slice(0, length)
    .join('')

export const generateRandomPassword = (): string => (
  [
    getRandomCharsFromString('0123456789', 4),
    getRandomCharsFromString('ABCDEFGHIJKLMNOPQRSTUVWXYZ', 6),
    getRandomCharsFromString('abcdefghijklmnopqrstuvwxyz', 6),
    getRandomCharsFromString('.,<>;:?&*!@#$%', 4),
  ]
    .join('')
    .split('')
    .sort(() => Math.random() - 0.5)
    .join('')
)