The PromiseRejectionEvent
interface represents events which are sent to the global script context when JavaScript Promise
s are rejected. These events are particularly useful for telemetry and debugging purposes.
For details on promise rejection events, see Promise rejection events in Using Promises.
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Constructor
PromiseRejectionEvent()
- Creates a
PromiseRejectionEvent
event, given the type of event (unhandledrejection
orrejectionhandled
) and other details.
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 toPromise.reject()
.
Methods
This interface has no unique methods; inherits methods from its parent Event
.
Events
rejectionhandled
- Fired when a JavaScript
Promise
is rejected, and after the rejection is handled by the promise's rejection handling code. unhandledrejection
- Fired when a JavaScript
Promise
is rejected but there is no rejection handler to deal with the rejection.
Examples
This simple example catches unhandled promise rejections and logs them for debugging purposes.
window.onunhandledrejection = function(e) {
console.log(e.reason);
}
Specifications
Specification | Status | Comment |
---|---|---|
HTML Living StandardThe definition of 'PromiseRejectionEvent' in that specification. | Living Standard | Initial definition. |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Update compatibility data on GitHub
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
PromiseRejectionEvent
|
Chrome
Full support 49 |
Edge
Full support ≤79 |
Firefox Full support 69 Full support 69 Full support 68 Disabled' From version 68: this feature is behind the |
IE
No support No |
Opera
Full support 36 |
Safari
Full support 11 |
WebView Android
Full support 49 |
Chrome Android
Full support 49 |
Firefox Android Full support 68 Full support 68 Disabled' From version 68: this feature is behind the |
Opera Android
Full support 36 |
Safari iOS
Full support 11.3 |
Samsung Internet Android
Full support 5.0 |
PromiseRejectionEvent() constructor
|
Chrome
Full support 49 |
Edge
Full support ≤79 |
Firefox Full support 69 Full support 69 Full support 68 Disabled' From version 68: this feature is behind the |
IE
No support No |
Opera
Full support 36 |
Safari
Full support 11 |
WebView Android
Full support 49 |
Chrome Android
Full support 49 |
Firefox Android Full support 68 Full support 68 Disabled' From version 68: this feature is behind the |
Opera Android
Full support 36 |
Safari iOS
Full support 11.3 |
Samsung Internet Android
Full support 5.0 |
promise
|
Chrome
Full support 49 |
Edge
Full support ≤79 |
Firefox Full support 69 Full support 69 Full support 68 Disabled' From version 68: this feature is behind the |
IE
No support No |
Opera
Full support 36 |
Safari
Full support 11 |
WebView Android
Full support 49 |
Chrome Android
Full support 49 |
Firefox Android Full support 68 Full support 68 Disabled' From version 68: this feature is behind the |
Opera Android
Full support 36 |
Safari iOS
Full support 11.3 |
Samsung Internet Android
Full support 5.0 |
reason
|
Chrome
Full support 49 |
Edge
Full support ≤79 |
Firefox Full support 69 Full support 69 Full support 68 Disabled' From version 68: this feature is behind the |
IE
No support No |
Opera
Full support 36 |
Safari
Full support 11 |
WebView Android
Full support 49 |
Chrome Android
Full support 49 |
Firefox Android Full support 68 Full support 68 Disabled' From version 68: this feature is behind the |
Opera Android
Full support 36 |
Safari iOS
Full support 11.3 |
Samsung Internet Android
Full support 5.0 |
Legend
- Full support
- Full support
- No support
- No support
- User must explicitly enable this feature.'
- User must explicitly enable this feature.
See also
- Promises
- Using promises
Promise
WindowEventHandlers.onrejectionhandled
WindowEventHandlers.onunhandledrejection
PromiseRejectionEvent by Mozilla Contributors is licensed under CC-BY-SA 2.5.