salix/loopback/util/validateNIF.js

const models = require('vn-loopback/server/server').models;
module.exports = async function(fi, isVies, countryFk) {
    const filter = {
        fields: ['code'],
        where: {id: countryFk}
    };
    const countryCode = fi.toUpperCase().substring(0, 2);
    const country = await models.Country.findOne(filter);
    const code = country ? country.code : null;
    if (isVies && countryCode == code)
        return false;
    return true;
};