JS stacktraces. The good, the bad, and the ugly.

http://blog.bugsnag.com/2014/01/12/js-stacktraces/

by cirwin • 13 years ago

29 8 13 years ago

blog.bugsnag.com

michaelwww2• 13 years ago

I'd like to try this, but not having a TypeScript definition file is a barrier.

foobar2k• 13 years ago

James from Bugsnag here, our notifer is fully open source (https://github.com/bugsnag/bugsnag-js) would gladly merge a pull request!

michaelwww2• 13 years ago

Good, if I do it I'll put it on Definitely Typed and send it your way to.

https://github.com/borisyankov/DefinitelyTyped

masswerk3• 13 years ago

Please mind that wrapping code in a try-block will send (at least some) JS-engines directly into interpreter mode (no compile-mode, no JIT-mode) and this will have severe effects on the execution speed. I would not recommend this for production!

cirwin2• 13 years ago

Do you have details on which engines will have this issue?

In the actual Bugsnag notifier we avoid adding try/catch in Chrome/Opera because they don't need it (it also breaks "stop on unhandled exception" in the console).

masswerk3• 13 years ago

To my humble knowledge this (interpreter mode) also applies to FF (which would be handled in the case of this application by the error-event anyway). I would consider it at least as a "legacy behavior". I think there is no JIT with try-blocks with any JS-engine.

I would suggest to do some speed tests with and without this wrapper.

Generally I would recommend to use a try-block only for some very small portions of code, if at all ... don't use them as a general tool ...

----

Some references:

* "In particular, the optimizing compiler [V8] currently bails out on functions with try {} catch {} blocks!"

http://www.html5rocks.com/en/tutorials/speed/v8/

* JIT, try, catch, see the "Browserscope" at end of page (mind the extreme performance gain for normal functions without try-catch with Chrome 31/32 -- yes, named functions are still the speediest):

http://jsperf.com/try-catch-jit/2

JS stacktraces. The good, the bad, and the ugly.

Related Stories