validar rut chile

def rut_validator(rut):
  rut = rut.replace(/\./g, '').replace('-', '')

  let dv = rut[rut.length - 1]
  let new_rut = rut.slice(0, rut.length - 1)

  let sum = 0
  let mul = 2

  for (let i = 1; i <= new_rut.length; i++) {
    let index = new_rut.length - i
    sum = sum + parseInt(new_rut[index]) * mul

    if (mul == 7) {
      mul = 2
    } else {
      mul = mul + 1
    }
  }

  let rest = sum % 11

  let digito
  if (rest == 1) {
    digito = 'k'
  } else if (rest == 0) {
    digito = '0'
  } else {
    digito = 11 - rest
  }

  if (digito == dv.toLowerCase()) {