Format CPF and CPNJ

format.js

const formatCPF = cpf => {
  const invalidCPF = !cpf || cpf.length !== 11;
  if (invalidCPF) return cpf;

  return cpf
    .replace(/[^\d]/g, '')
    .replace(/(\d{3})(\d{3})(\d{3})(\d{2})/, '$1.$2.$3-$4');
};

const formatCNPJ = cnpj => {
  const invalidCNPJ = !cnpj || cnpj.length !== 14;
  if (invalidCNPJ) return cnpj;

  return cnpj
    .replace(/[^\d]/g, '')
    .replace(/(\d{2})(\d{3})(\d{3})(\d{4})(\d{2})/, '$1.$2.$3/$4-$5');
};