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PromiseRejectionEvent

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

Constructor

PromiseRejectionEvent()
Creates a PromiseRejectionEvent event with the given parameters.

Properties

Also inherits properties from its parent Event.

PromiseRejectionEvent.promise Read only
The JavaScript Promise that was rejected.
PromiseRejectionEvent.reason Read only
A value or Object indicating why the promise was rejected, as passed to Promise.reject().

Methods

This interface has no unique methods; inherits methods from its parent Event.

Events

unhandledrejection
Fired when a JavaScript Promise is rejected but there is no rejection handler to deal with the rejection.
rejectionhandled
Fired when a JavaScript Promise is rejected, and after the rejection is handled by the promise's rejection handling code.

Examples

window.onunhandledrejection = function(e) {
  console.log(e.reason);
}

Specifications

Specification Status Comment
HTML Living Standard
The definition of 'PromiseRejectionEvent' in that specification.
Living Standard Initial definition.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support 49 No support[1] No support No support No support
Feature Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support No support No support[1] No support No support No support

[1] In Firefox, this is implemented but disabled by default. To turn it on, go to about:config and set the dom.promise_rejection_events.enabled pref to true.

See also

Document Tags and Contributors

 Contributors to this page: Sheppy, chrisdavidmills, fscholz
 Last updated by: Sheppy,