export function isCPF(cpf: string | null | undefined): boolean {
  if (!cpf) return false

  cpf = cpf.replace(/[.-]/g, '')
  if (cpf.length !== 11 || /^(\d)\1{10}$/.test(cpf)) return false

  let sum = 0,
    rest
  for (let i = 1; i <= 9; i++) sum += parseInt(cpf[i - 1]) * (11 - i)
  rest = (sum * 10) % 11
  if (rest === 10 || rest === 11) rest = 0
  if (rest !== parseInt(cpf[9])) return false

  sum = 0
  for (let i = 1; i <= 10; i++) sum += parseInt(cpf[i - 1]) * (12 - i)
  rest = (sum * 10) % 11
  if (rest === 10 || rest === 11) rest = 0
  return rest === parseInt(cpf[10])
}