// prep-work const _data = new Uint8Array(16); const _hex = []; for (let i = 0; i < 256; i++) { _hex.push(i.toString(16).padStart(2, '0')); } // todo@jrieken - with node@15 crypto#getRandomBytes is available everywhere, https://developer.mozilla.org/en-US/docs/Web/API/Crypto/getRandomValues#browser_compatibility let _fillRandomValues; if (typeof crypto === 'object' && typeof crypto.getRandomValues === 'function') { // browser _fillRandomValues = crypto.getRandomValues.bind(crypto); } else { _fillRandomValues = function (bucket) { for (let i = 0; i < bucket.length; i++) { bucket[i] = Math.floor(Math.random() * 256); } return bucket; }; } export function generateUuid() { // get data _fillRandomValues(_data); // set version bits _data[6] = (_data[6] & 0x0f) | 0x40; _data[8] = (_data[8] & 0x3f) | 0x80; // print as string let i = 0; let result = ''; result += _hex[_data[i++]]; result += _hex[_data[i++]]; result += _hex[_data[i++]]; result += _hex[_data[i++]]; result += '-'; result += _hex[_data[i++]]; result += _hex[_data[i++]]; result += '-'; result += _hex[_data[i++]]; result += _hex[_data[i++]]; result += '-'; result += _hex[_data[i++]]; result += _hex[_data[i++]]; result += '-'; result += _hex[_data[i++]]; result += _hex[_data[i++]]; result += _hex[_data[i++]]; result += _hex[_data[i++]]; result += _hex[_data[i++]]; result += _hex[_data[i++]]; return result; }