documentid-checksum-validator/lib/BR/cpf.js

checksum validation for government doc ids

// Function to validate the CPF in BR

'use strict';

Object.defineProperty(exports, '__esModule', {
    value: true
});
exports['default'] = isValidDocId;

function isValidDocId(value) {
    var textFieldValue = value;
    // Function to validate the CPF in BR
    var valueArray = textFieldValue.split('');
    if (valueArray.length < 11 || valueArray.length > 11 || value === '11111111111' || value === '22222222222' || value === '33333333333' || value === '44444444444' || value === '55555555555' || value === '66666666666' || value === '77777777777' || value === '88888888888' || value === '99999999999' || value === '00000000000') {
        return false;
    }

    var CPF_SIZE = 10;
    var sum = [0, 0];
    var isTenthDigitZero = false;
    var isEleventhDigitZero = false;

    /*
        below loop is to store result of the below two equation
        Consider the CPF written as 11 digits as c[1] c[2] c[3] c[4] c[5] c[6] c[7] c[8] c[9] dv[1] dv[2], then
        equation I : c[1]*10 + c[2]*9 + c[3]*8 + c[4]*7 + c[5]*6 + c[6]*5 + c[7]*4 + c[8]*3 + c[9]*2 + dv[1]
        equation II : c[2]*10 + c[3]*9 + c[4]*8 + c[5]*7 + c[6]*6 + c[7]*5 + c[8]*4 + c[9]*3 + dv[1]*2 + dv[2]
    */
    for (var i = 0; i < 2; i++) {
        var m = 10; // Multiplier which is initially set to 10
        CPF_SIZE += i; // Incremented bcoz we have to include last digit for the equation 2
        var x = undefined;
        // below loop is to multiply the each digits (As per equation 1 and 2) with the multiplier
        for (var j = i; j < CPF_SIZE; j++) {
            x = valueArray[j];
            sum[i] = sum[i] + x * m--;
            if (i === 0 && j === 9) {
                isTenthDigitZero = x === 0;
            } else if (i === 1 && j === 10) {
                isEleventhDigitZero = x === 0;
            }
        }
    }
    // get the modulus of 11 with the result from equation 1 and 2
    var mod1 = sum[0] % 11;
    var mod2 = sum[1] % 11;
    // return CPF validation as true only when Modulus 11 of equation I and II is 0 or
    // if  Modulus of 11 is 1 and 10th digit is 0(in case of equation I) and 11th digit (in case of equation II) is 0
    return (mod1 === 0 || mod1 === 1 && isTenthDigitZero) && (mod2 === 0 || mod2 === 1 && isEleventhDigitZero);
}

module.exports = exports['default'];