import { is } from "cuit";

const isValid = is("20-21834641-4"); // => true

import { guess } from "cuit";

const dni = "21834641";

// "M" for male, "F" for female and "E" for business / "Persona Jurídica"
const cuit = guess(dni, "M"); // => 20-21834641-4

import { format } from "cuit";

const formatted = format("20218346414", "."); // => 20.21834641.4