PromiseRejectionEvent
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.
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 |
---|
HTML Standard # the-promiserejectionevent-interface |
Browser compatibility
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