Function poll

async/poll.ts:69–95

(
  fn: () => T,
  isDone: (result: Awaited<T>) => boolean,
  options: PollOptions = {},
)

 * @returns The result of `fn` when `isDone` returns `true`.
 */
export async function poll<T>(
  fn: () => T,
  isDone: (result: Awaited<T>) => boolean,
  options: PollOptions = {},
): Promise<Awaited<T>> {
  const { signal, interval = 1000 } = options;

  if (!Number.isFinite(interval) || interval < 0) {
    throw new RangeError(
      `Cannot poll as 'interval' must be a non-negative finite number: current value is ${interval}`,
    );
  }

  const delayOptions = signal ? { signal } : undefined;

  while (true) {
    signal?.throwIfAborted();

    const result = await fn();

    if (isDone(result)) {
      return result;
    }

    await delay(interval, delayOptions);
  }
}