parpeoficial/stackerjs-utils

export default function CNPJ(cnpj) 
{
    this.validate = () => 
    {
        let value = this.clear();
        if (value.length !== 14 || /^(\d)\1+$/.test(value)) return false;

        let length = value.length - 2;
        let numbers = value.substring(0, length);
        let digits = value.substring(length);
        let summ = 0;

        let pos = length - 7;

        for (let i = length; i >= 1; i--) 
        {
            summ += numbers.charAt(length - i) * pos--;
            if (pos < 2) pos = 9;
        }

        let result = summ % 11 < 2 ? 0 : 11 - summ % 11;
        if (result != digits.charAt(0)) return false;

        length = length + 1;
        numbers = value.substring(0, length);
        summ = 0;
        pos = length - 7;

        for (let i = length; i >= 1; i--) 
        {
            summ += numbers.charAt(length - i) * pos--;
            if (pos < 2) pos = 9;
        }
        result = summ % 11 < 2 ? 0 : 11 - summ % 11;

        if (result != digits.charAt(1)) return false;

        return true;
    };

    this.clear = () => 
    {
        return cnpj.replace(/\D/g, "");
    };

    this.format = () => 
    {
        let value = this.clear();
        return value.replace(
            /^(\d{2})(\d{3})(\d{3})(\d{4})(\d{2})$/,
            "$1.$2.$3/$4-$5"
        );
    };

    return this;
}