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CompleteNodeJS/notes-app/node_modules/validator/lib/isISSN.js
Jason Williams 6528d7204a Section 20
2019-08-11 12:15:16 -06:00

34 lines
1013 B
JavaScript

'use strict';
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.default = isISSN;
var _assertString = require('./util/assertString');
var _assertString2 = _interopRequireDefault(_assertString);
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
var issn = '^\\d{4}-?\\d{3}[\\dX]$';
function isISSN(str) {
var options = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};
(0, _assertString2.default)(str);
var testIssn = issn;
testIssn = options.require_hyphen ? testIssn.replace('?', '') : testIssn;
testIssn = options.case_sensitive ? new RegExp(testIssn) : new RegExp(testIssn, 'i');
if (!testIssn.test(str)) {
return false;
}
var digits = str.replace('-', '').toUpperCase();
var checksum = 0;
for (var i = 0; i < digits.length; i++) {
var digit = digits[i];
checksum += (digit === 'X' ? 10 : +digit) * (8 - i);
}
return checksum % 11 === 0;
}
module.exports = exports['default'];