import validate from './validate.js'; /** * Convert array of 16 byte values to UUID string format of the form: * XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX */ const byteToHex = []; for (let i = 0; i < 256; ++i) { byteToHex.push((i + 0x100).toString(16).slice(1)); } export function unsafeStringify(arr, offset = 0) { // Note: Be careful editing this code! It's been tuned for performance // and works in ways you may not expect. See https://github.com/uuidjs/uuid/pull/434 // // Note to future-self: No, you can't remove the `toLowerCase()` call. // REF: https://github.com/uuidjs/uuid/pull/677#issuecomment-1757351351 return (byteToHex[arr[offset + 0]] + byteToHex[arr[offset + 1]] + byteToHex[arr[offset + 2]] + byteToHex[arr[offset + 3]] + '-' + byteToHex[arr[offset + 4]] + byteToHex[arr[offset + 5]] + '-' + byteToHex[arr[offset + 6]] + byteToHex[arr[offset + 7]] + '-' + byteToHex[arr[offset + 8]] + byteToHex[arr[offset + 9]] + '-' + byteToHex[arr[offset + 10]] + byteToHex[arr[offset + 11]] + byteToHex[arr[offset + 12]] + byteToHex[arr[offset + 13]] + byteToHex[arr[offset + 14]] + byteToHex[arr[offset + 15]]).toLowerCase(); } function stringify(arr, offset = 0) { const uuid = unsafeStringify(arr, offset); // Consistency check for valid UUID. If this throws, it's likely due to one // of the following: // - One or more input array values don't map to a hex octet (leading to // "undefined" in the uuid) // - Invalid input values for the RFC `version` or `variant` fields if (!validate(uuid)) { throw TypeError('Stringified UUID is invalid'); } return uuid; } export default stringify;