/** * The function `asyncAuth(callback)` accepts a callback, * which can receive an error (as the first argument) and data * from the backend (as the second argument). * asyncAuth((error, data) => {}); * * You need to implement the `auth()` function, * which calls `asyncAuth()`, but returns a Promise. * * @returns {Promise} */ function auth() { // asyncAuth((error, data) => {}); } /** * The function `tryAuth()` uses `auth()` and, in case of an error, * makes N additional attempts. * If all attempts fail - return the last error. * * @returns {Promise} */ function tryAuth(n) { }

javascript function auth() { return new Promise((resolve, reject) => { asyncAuth((error, data) => { if (error) { reject(error); } else { resolve(data); } }); }); }

async function tryAuth(n) { let lastError; for (let i = 0; i <= n; i++) { try { const result = await auth(); return result; } catch (error) { lastError = error; if (i === n) { throw lastError; } } } }

The `auth()` function wraps the call to `asyncAuth` in a Promise to use the modern async/await syntax. The `tryAuth(n)` function attempts to call `auth()` up to `n` times in case of an error, and if all attempts fail, it throws the last error.