raven-js with jQuery plugin always throws "Uncaught TypeError: Expecting a function in instanceof check, but got #<Object>"

[jpw]

I'm developing a hybrid app (everything is loaded off the file system except our data calls), and it's pretty complex with several thousand lines of JS.

Using;
//cdn.ravenjs.com/1.1.16/jquery,native/raven.min.js

I am instantiating raven-js using;
Raven.config( DSN, options ).install();

...where my options are a few tags. Everything works fine, it logs to the backend great.

I am not handling window.onerror myself, I am leaving everything up to raven-js for now.

I am throwing errors in two ways to test, manually with a DIV with;

onclick="try{var v=new Jasdfasd;}catch(e){Raven.captureException(e);};"

And in one of the routes for my app with;

var v = new DoesntExistRavenTest();

If I use raven-js without the jQuery plugin it logs, it's not very useful as it bubbling up to window.onerror as the docs say, but it works.

With the plugin it always throws this error in raven-js itself

Uncaught TypeError: Expecting a function in instanceof check, but got #<Object> VM12497:6104
O.captureException VM12497:6104
d VM12497:6104
n.event.dispatch (index):13
r.handle

"n" & "r" are in my minified jQuery source (v 2.1.1 although I tried it with 1.11 as well, no diff)
"O.captureException" is in the minified raven-js source.

[mattrobenolt]

Can you run this against the unminified raven.js ? Also, is this somewhere that I can see and reproduce?

Thanks.

[mattrobenolt]

Actually, I'm guessing it's just simply this:

https://github.com/getsentry/raven-js/blob/master/src/raven.js#L235

What browser is this happening in?

[mattrobenolt]

I'm reading random thing on the internet that are suggesting that instanceof in general is not that great. I'll see another way to check if it's an Error object by feature detection.

[jpw]

Thanks for having a look! :)
This is in the latest Chrome, Version 36.0.1985.125 on OS X. Sadly it's not somewhere you can see.

I'm not sure how to use the unminified raven-js source with it's unminified jQuery plugin, but your line number guess looks correct -- in the minified source it's;

captureException:function(a,b){if(!(a instanceof Error))return O.captureMessage(a,b);

...the following console tinkering seem to illustrate what's going on;

> try{var v=new Jasdfasd;}catch(e){ console.log(e instanceof Error)}
< TypeError: Expecting a function in instanceof check, but got #<Object>
> try{var v=new Jasdfasd;}catch(e){ console.log(e instanceof ReferenceError)}
< true VM14173:2
< undefined
> ReferenceError instanceof Error
< TypeError: Expecting a function in instanceof check, but got #<Object>
> ReferenceError
< function ReferenceError() { [native code] }
> Error
< Object {init: function}

[mattrobenolt]

Interesting... that seems to be a bug in Chrome. I run the beta builds and it doesn't error like that. Neither does Firefox. :/

That's especially weird because in your case... e is an Error. I was expecting you to be passing something weird into captureException explicitly or something.

Edit: Ran in Chrome Version 37.0.2062.58 beta fwiw and just returns true as expected.

[mattrobenolt]

@jpw So this is really messed up and reinforces that I think it's a bug in Chrome, or something on your page that's overriding the Error object.

For example, this is what's happening: 1 instanceof {} The error is stemming from the fact that Error itself isn't a function.

Can you do a console.log(Error) and see what you get?

[jpw]

Aaargh yes, I've just found something clobbering Error in the code base facepalm

Sorry for any trouble!

[mattrobenolt]

Oh man, don't do that! That'll probably cause you all sorts of problems. ;)

Either way, I got a better isError check out of it anyways.