Safely Handling Async Promise Failures with Tupled Fallbacks

type AsyncResult<T, E = Error> = Promise<[E, null] | [null, T]>;
 
async function safeResult<T, E = Error>(promise: Promise<T>): AsyncResult<T, E> {
  try {
    const data = await promise;
    return [null, data];
  } catch (error) {
    return [error as E, null];
  }
}
 
async function demo() {
  const task = Promise.reject(new Error('Network loss'));
  const [err, result] = await safeResult(task);
  if (err) {
    console.error('Caught safely:', err.message);
    return;
  }
  console.log('Success:', result);
}