react-native/local-cli/core/windows/generateGUID.js

const s4 = () => {
  return Math.floor((1 + Math.random()) * 0x10000)
    .toString(16)
    .substring(1);
};

module.exports = function generateGUID() {
  return s4() + s4() + '-' + s4() + '-' + s4() + '-' +
    s4() + '-' + s4() + s4() + s4();
};