The PromiseRejectionEvent interface represents events which are fired when JavaScript Promises are rejected. These events are particularly useful for telemetry and debugging purposes.

API Events events HTML DOM Interface JavaScript PromiseRejectionEvent Promises Reference

The PromiseRejectionEvent() constructor returns a newly created PromiseRejectionEvent, which represents events fired when a JavaScript Promise is rejected.

API Constructor events Events HTML DOM JavaScript PromiseRejectionEvent Promises Reference

The PromiseRejectionEvent.promise read-only property indicates the JavaScript Promise which has been rejected. You can examine the event's PromiseRejectionEvent.reason property to learn why the promise was rejected.

API events Events HTML DOM JavaScript Promise PromiseRejectionEvent Promises Property Reference

The PromiseRejectionEvent.reason read-only property is any JavaScript value or Object which provides the reason passed into Promise.reject(). This in theory provides information about why the promise was rejected.

API Events events HTML DOM JavaScript PromiseRejectionEvent Promises Property reason Reference