34 lines
935 B
JavaScript
34 lines
935 B
JavaScript
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"use strict";
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Object.defineProperty(exports, "__esModule", {
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value: true
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});
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exports.default = isLuhnNumber;
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var _assertString = _interopRequireDefault(require("./util/assertString"));
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function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
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function isLuhnNumber(str) {
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(0, _assertString.default)(str);
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var sanitized = str.replace(/[- ]+/g, '');
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var sum = 0;
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var digit;
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var tmpNum;
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var shouldDouble;
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for (var i = sanitized.length - 1; i >= 0; i--) {
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digit = sanitized.substring(i, i + 1);
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tmpNum = parseInt(digit, 10);
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if (shouldDouble) {
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tmpNum *= 2;
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if (tmpNum >= 10) {
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sum += tmpNum % 10 + 1;
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} else {
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sum += tmpNum;
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}
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} else {
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sum += tmpNum;
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}
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shouldDouble = !shouldDouble;
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}
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return !!(sum % 10 === 0 ? sanitized : false);
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}
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module.exports = exports.default;
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module.exports.default = exports.default;
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