documentid-checksum-validator/lib/RU/ssn.js

checksum validation for government doc ids

'use strict';

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

function isValidDocId(value) {
    var valueArray = value.split('');
    var valid = true;

    if (valueArray.length < 11 || valueArray.length > 11) {
        valid = false;
    } else {
        var lastTwoDigit = valueArray[9] * 10 + valueArray[10] * 1;
        // standard multiplier for controling the last two digits in ssn
        var multiplierString = [9, 8, 7, 6, 5, 4, 3, 2, 1];
        var sum = 0;

        for (var i = 0; i < multiplierString.length; i++) {
            sum += multiplierString[i] * valueArray[i];
        }
        if (sum < 100 && sum === lastTwoDigit) {
            valid = true;
        }if ((sum === 100 || sum === 101) && lastTwoDigit === 0) {
            valid = true;
        }if (sum > 102 && sum - 101 === lastTwoDigit) {
            valid = true;
        } else {
            valid = false;
        }
    }
    return valid;
}

module.exports = exports['default'];