text: define(["require", "exports"], function (require, exports) {
      "use strict";
      Object.defineProperty(exports, "__esModule", { value: true });
      function issn() {
          return {
              validate: function (input) {
                  if (input.value === '') {
                      return { valid: true };
                  }
                  if (!/^\d{4}\-\d{3}[\dX]$/.test(input.value)) {
                      return { valid: false };
                  }
                  var chars = input.value.replace(/[^0-9X]/gi, '').split('');
                  var length = chars.length;
                  var sum = 0;
                  if (chars[7] === 'X') {
                      chars[7] = '10';
                  }
                  for (var i = 0; i < length; i++) {
                      sum += parseInt(chars[i], 10) * (8 - i);
                  }
                  return { valid: (sum % 11 === 0) };
              },
          };
      }
      exports.default = issn;
  });
  