Uint8Array helper for encoding and decoding, similar to Node.js `Buffer`

uint8array.js

// Helper methods
const hex_decode = (s) =>
  Uint8Array.from(s.match(/.{1,2}/g).map((b) => parseInt(b, 16)));

const hex_encode = (u) =>
  Array.from(u).map((b) => b.toString(16).padStart(2, '0')).join('')

const ascii_decode = (s) =>
  Uint8Array.from(Array.from(s).map((l) => l.charCodeAt(0)))

const ascii_encode = (u) =>
  Array.from(u).map((l) => String.fromCharCode(l)).join('')

const u8ToB64 = (u) =>
  btoa(String.fromCharCode(...u))

const b64Tou8 = (b) =>
  Uint8Array.from(atob(b), c => c.charCodeAt(0))

const b64ToB64URL = (s) =>
  s.replace(/\+/g, '-').replace(/\//g, '_')

const b64URLtoB64 = (s) =>
  s.replace(/-/g, '+').replace(/_/g, '/')