WindowEventHandlers.onunhandledrejection

The onunhandledrejection property of the WindowEventHandlers mixin is the EventHandler for processing unhandledrejection events. These events are raised for unhandled Promise rejections.

window.onunhandledrejection = function;

function is an EventHandler or function to call when unhandledrejection events are received by the window. The event handler receives as an input parameter as a PromiseRejectionEvent.

This example logs unhandled rejections' reason values to the console.

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