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

57 lines
1.4 KiB
JavaScript

'use strict';
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.default = isISBN;
var _assertString = require('./util/assertString');
var _assertString2 = _interopRequireDefault(_assertString);
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
var isbn10Maybe = /^(?:[0-9]{9}X|[0-9]{10})$/;
var isbn13Maybe = /^(?:[0-9]{13})$/;
var factor = [1, 3];
function isISBN(str) {
var version = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : '';
(0, _assertString2.default)(str);
version = String(version);
if (!version) {
return isISBN(str, 10) || isISBN(str, 13);
}
var sanitized = str.replace(/[\s-]+/g, '');
var checksum = 0;
var i = void 0;
if (version === '10') {
if (!isbn10Maybe.test(sanitized)) {
return false;
}
for (i = 0; i < 9; i++) {
checksum += (i + 1) * sanitized.charAt(i);
}
if (sanitized.charAt(9) === 'X') {
checksum += 10 * 10;
} else {
checksum += 10 * sanitized.charAt(9);
}
if (checksum % 11 === 0) {
return !!sanitized;
}
} else if (version === '13') {
if (!isbn13Maybe.test(sanitized)) {
return false;
}
for (i = 0; i < 12; i++) {
checksum += factor[i % 2] * sanitized.charAt(i);
}
if (sanitized.charAt(12) - (10 - checksum % 10) % 10 === 0) {
return !!sanitized;
}
}
return false;
}
module.exports = exports['default'];