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- "use strict";
- Object.defineProperty(exports, "__esModule", {
- value: true
- });
- exports.default = isISBN;
- var _assertString = _interopRequireDefault(require("./util/assertString"));
- function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
- var possibleIsbn10 = /^(?:[0-9]{9}X|[0-9]{10})$/;
- var possibleIsbn13 = /^(?:[0-9]{13})$/;
- var factor = [1, 3];
- function isISBN(isbn, options) {
- (0, _assertString.default)(isbn); // For backwards compatibility:
- // isISBN(str [, version]), i.e. `options` could be used as argument for the legacy `version`
- var version = String((options === null || options === void 0 ? void 0 : options.version) || options);
- if (!(options !== null && options !== void 0 && options.version || options)) {
- return isISBN(isbn, {
- version: 10
- }) || isISBN(isbn, {
- version: 13
- });
- }
- var sanitizedIsbn = isbn.replace(/[\s-]+/g, '');
- var checksum = 0;
- if (version === '10') {
- if (!possibleIsbn10.test(sanitizedIsbn)) {
- return false;
- }
- for (var i = 0; i < version - 1; i++) {
- checksum += (i + 1) * sanitizedIsbn.charAt(i);
- }
- if (sanitizedIsbn.charAt(9) === 'X') {
- checksum += 10 * 10;
- } else {
- checksum += 10 * sanitizedIsbn.charAt(9);
- }
- if (checksum % 11 === 0) {
- return true;
- }
- } else if (version === '13') {
- if (!possibleIsbn13.test(sanitizedIsbn)) {
- return false;
- }
- for (var _i = 0; _i < 12; _i++) {
- checksum += factor[_i % 2] * sanitizedIsbn.charAt(_i);
- }
- if (sanitizedIsbn.charAt(12) - (10 - checksum % 10) % 10 === 0) {
- return true;
- }
- }
- return false;
- }
- module.exports = exports.default;
- module.exports.default = exports.default;
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