55 lines
1.4 KiB
Plaintext
55 lines
1.4 KiB
Plaintext
import assertString from './util/assertString';
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var possibleIsbn10 = /^(?:[0-9]{9}X|[0-9]{10})$/;
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var possibleIsbn13 = /^(?:[0-9]{13})$/;
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var factor = [1, 3];
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export default function isISBN(isbn, options) {
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assertString(isbn); // For backwards compatibility:
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// isISBN(str [, version]), i.e. `options` could be used as argument for the legacy `version`
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var version = String((options === null || options === void 0 ? void 0 : options.version) || options);
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if (!(options !== null && options !== void 0 && options.version || options)) {
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return isISBN(isbn, {
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version: 10
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}) || isISBN(isbn, {
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version: 13
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});
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}
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var sanitizedIsbn = isbn.replace(/[\s-]+/g, '');
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var checksum = 0;
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if (version === '10') {
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if (!possibleIsbn10.test(sanitizedIsbn)) {
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return false;
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}
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for (var i = 0; i < version - 1; i++) {
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checksum += (i + 1) * sanitizedIsbn.charAt(i);
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}
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if (sanitizedIsbn.charAt(9) === 'X') {
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checksum += 10 * 10;
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} else {
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checksum += 10 * sanitizedIsbn.charAt(9);
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}
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if (checksum % 11 === 0) {
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return true;
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}
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} else if (version === '13') {
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if (!possibleIsbn13.test(sanitizedIsbn)) {
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return false;
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}
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for (var _i = 0; _i < 12; _i++) {
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checksum += factor[_i % 2] * sanitizedIsbn.charAt(_i);
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}
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if (sanitizedIsbn.charAt(12) - (10 - checksum % 10) % 10 === 0) {
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return true;
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}
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}
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return false;
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} |