Função para validar CPF em TypeScript

validation-cpf.ts

function isValidCPF(value: string) {
    if (typeof value !== 'string') {
    return false;
  }
   
  value = value.replace(/[^\d]+/g, '');
  
  if (value.length !== 11 || !!value.match(/(\d)\1{10}/)) {
    return false;
  }

  const values = value.split('').map(el => +el);
  const rest = (count) => (values.slice(0, count-12).reduce( (soma, el, index) => (soma + el * (count-index)), 0 )*10) % 11 % 10;

  return rest(10) === values[9] && rest(11) === values[10];
}