Sometimes, we want to time out a Promise if failed to complete in time with Node.js and JavaScript.

In this article, we’ll look at how to time out a Promise if failed to complete in time with Node.js and JavaScript.

How to time out a Promise if failed to complete in time with Node.js and JavaScript?

To time out a Promise if failed to complete in time with Node.js and JavaScript, we use the Promise.race method.

For instance, we write

const withTimeout = (millis, promise) => {
  const timeout = new Promise((resolve, reject) =>
    setTimeout(() => reject(`Timed out after ${millis} ms.`), millis)
  );
  return Promise.race([promise, timeout]);
};

to define the withTimeout function.

In it, we create the timeout promise, which calls setTimeout callback when millis milliseconds has elapsed.

We call reject to reject the promise.

Then we call Promise.race with an array with the promise we want to run and the timeout promise.

Then the result of the promise that finishes first is returned as a promise.

Conclusion

To time out a Promise if failed to complete in time with Node.js and JavaScript, we use the Promise.race method.