WindowEventHandlers.onunhandledrejection - Web APIs
the onunhandledrejection property of the windoweventhandlers mixin is the eventhandler for processing unhandledrejection events.
... syntax window.onunhandledrejection = function; value function is an eventhandler or function to call when unhandledrejection events are received by the window.
... window.onunhandledrejection = function(e) { console.log(e.reason); } specifications specification status comment html living standardthe definition of 'onunhandledrejection' in that specification.

Window: unhandledrejection event - Web APIs
bubbles no cancelable yes interface promiserejectionevent event handler property onunhandledrejection usage notes allowing the unhandledrejection event to bubble will eventually result in an error message being output to the console.
... window.addeventlistener("unhandledrejection", event => { console.warn(`unhandled promise rejection: ${event.reason}`); }); you can also use the onunhandledrejection event handler property to set up the event listener: window.onunhandledrejection = event => { console.warn(`unhandled promise rejection: ${event.reason}`); }; preventing default handling many environments (such as node.js) report unhandled promise rejections to the console by default.

Window - Web APIs
see storage event globaleventhandlers.onsubmit called when a form is submitted windoweventhandlers.onunhandledrejection an event handler for unhandled promise rejection events.
... also available using the onunhandledrejection event handler property.

HTMLBodyElement - Web APIs
windoweventhandlers.onunhandledrejection an eventhandler representing the code executed when the unhandledrejection event is raised, indicating that a promise was rejected but the rejection was not handled.

Index - Web APIs
5091 windoweventhandlers.onunhandledrejection api, event handler, html dom, promises, property, reference, windoweventhandlers, events, onunhandledrejection the onunhandledrejection property of the windoweventhandlers mixin is the eventhandler for processing unhandledrejection events.

PromiseRejectionEvent.promise - Web APIs
window.onunhandledrejection = function(event) { if (event.reason.code && event.reason.code == "module not ready") { window.requestidlecallback(function(deadline) { loadmodule(event.reason.modulename) .then(performstartup); }); event.preventdefault(); } } specifications specification status comment html living standardthe definition of 'promiserejectionevent.promise...

PromiseRejectionEvent.reason - Web APIs
examples window.onunhandledrejection = function(e) { console.log(e.reason); } specifications specification status comment html living standardthe definition of 'promiserejectionevent.reason' in that specification.

PromiseRejectionEvent - Web APIs
window.onunhandledrejection = function(e) { console.log(e.reason); } specifications specification status comment html living standardthe definition of 'promiserejectionevent' in that specification.

WindowEventHandlers - Web APIs
windoweventhandlers.onunhandledrejection is an eventhandler representing the code to be called when the unhandledrejection event is raised, indicating that a promise was rejected but the rejection was not handled.

Worker - Web APIs
also available using the onunhandledrejection event handler property.

WorkerGlobalScope - Web APIs
also available via the workerglobalscope.onunhandledrejection property.