How to catch uncaught exception in Promise

Question

Is there any way to globally catch all exceptions including Promise exceptions. Example:

    window.onerror = function myErrorHandler(errorMsg, url, lineNumb         


        

Answer 1

Update, native promises now do the following in most browsers:

window.addEventListener("unhandledrejection", function(promiseRejectionEvent) { 
    // handle error here, for example log   
});

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We were just discussing this the other day.

Here is how you'd do this with bluebird:

window.onpossiblyunhandledexception = function(){
    window.onerror.apply(this, arguments); // call
}

window.onerror = function(err){
    console.log(err); // logs all errors
}

With Bluebird it's also possible to use Promise.onPossiblyUnhandledRejection. The calls for done are not needed as the library will detect unhandled rejection itself unlike Q (UPDATE 2016 - I now wrote code for Q and it does this).

As for native promises - they will eventually report to either window.onerror or a new handler but the specification process is not yet done - you can follow it here.