At 2010-09-30 20:35, Trevor Parscal wrote:
[...]
- Where end users report platform-specific JavaScript errors, it may
be useful to be able to match the line number of the error with something meaningful.
The usefulness of this is attached to the idea the most important part of the error message is the line number. In some browsers (such as many versions of IE) the line numbers aren't even correct. Besides, as I have said already, over and over, combination is going to throw off line numbers anyways, not just making them higher, but depending on the user's preferences they may be totally different from one user to another. Line numbers in production mode (debug=false) are useless no matter how much white-space is preserved.
To my experience something is better then nothing. IE (old one that is) is usually wrong when you have either long lines (ekhem ;-)) and have code inside script tags (instead of outer files). Picture this:
1. A user says his browser reports an error. 2. I ask for the browser and other stuff... 3. I don't see the problem. 4. He tries out debug mode and it's fine. 5. I search through his code...
The problem with fully minified without any vertical white space code to me is that you cannot read this. Well I can't and Firebug can't and any other debugger AFAIK. If something comes up it will be almost impossible to catch.
Since the cost of adding line breaks is fairly small, the contention was that it was a fair compromise between size and developer (and tech supporter) sanity. So I took those comments on board and implemented it shortly after the branch merge.
We should probably calculate just how small that cost is before we start making asumptions based on it being "fairly small". Also, as I have been saying, the production mode (debug=false) is only going to become more optimized in the future, further reducing the value of line numbers.
OK, now I've calculated it...
On a normal page view with the Vector skin and the Vector extension turned on there's a 2KB difference. On an edit page with the Vector skin and Vector and WikiEditor extensions there's a 4KB difference.
While adding 2KB to a request for a person in a remote corner of the world on a 56k modem will only add about 0.3 seconds to the download, sending 2,048 extra bytes to 350 million people each month increases our bandwidth by about 668 gigabytes a month. I don't know what that kind of bandwidth costs the foundation, but it's not free.
OK. It's not free, the question is it worth the effort and are you really calculating this correctly? I think it would be worth it as a just-in-case thing. Also JS is usually cached and actually get stuck in cache for days. And just to be sure - did you calculated gziped version difference or plain?
Plus developers will probably stick to debug mode if won't provide something in the middle. Yes, I can't speak for all, but personally I work on code (small tweaks) from time to time while I'm not doing other stuff in the minute. Always changing to debug mode to debug code will not be very productive to me. That's why I wrote my loader and I was hoping that you will add some stuff from it to the loader so I can use it and so the RL can be useful to me (in non-wikimedia use cases too).
Again I'm sure you are confident with your code and code of your colleagues and I'm not saying you screwed something up. I'm just saying something will eventually get screwed up just because it always does. That's why programmers are always needed isn't it ;-).
Regards, Nux.