Best way to capture JavaScript errors in production? [closed]

Question

I've got a serious JavaScript problem that is hard to reproduce in any of our dev/test/prod environments. Nonetheless, it is being reported consistently by our customers. Sometimes we think it's browser specific -- sometimes we think it's action specific -- sometimes we think it's cookie related. It's a tough one and we're getting pulled in too many different directions and they are all coming up short.

We believe the problem occurs in one of our main JavaScript files -- but that file is enormous. We've pin-pointed other problems in the past in this file -- and guarded against future problems using try/catch blocks successfully -- but, at this time we're very unsure where these newer problems are occurring.

We've searched through our server logs and the information we are finding there is not useful.

I am wondering if utilizing a JavaScript logging framework would help our problems. Will implementing something like "log4javascript" capture/log the activity of our users, not just us? Any advice? Anyone else been in this situation? What strategies did you employ to better understand your errors?

Answer 1

log4javascript's AjaxAppender can be used to send log messages to the server.

var log = log4javascript.getLogger("serverlog");
var ajaxAppender = new log4javascript.AjaxAppender("http://example.com/clientlogger");
log.addAppender(ajaxAppender);

You could put informational logging calls in your code and add a window.onerror handler to catch errors not caught by try/catch blocks in your code:

window.onerror = function(errorMsg, url, lineNumber) {
    log.fatal("Uncaught error " + errorMsg + " in " + url + ", line " + lineNumber);
};

You will also need to create something on the server to process the logging requests from the browser.

Full disclosure: I am the author of log4javascript.

Answer 2

1. Take a look at errorception

http://errorception.com/

2. Also try Atatus - It is a new JavaScript Error Tracking Service along with Real User Monitoring (RUM) for modern web apps.

https://www.atatus.com/

3. Also BugSense released an html5 version of their bug tracking

https://www.bugsense.com/docs/html5

So, you get a pretty interface to track them