I have just taken over maintenance of a large web application which is over 10,000 lines of Javascript.
At the moment it runs on Firefox 3.5+, Safari 4+ and Chrome and I have to make it work with IE8.
I am a very experienced programmer but I only have a little Javascript experience - although I have been introduced to the dubious pleasure of quirksmode and I have a copy of Javascript The Good Parts.
The Javascript uses a lot of JQuery (and so great chunks of it are good to go).
I want to go about it in a systematic manner and would like advice on how to structure my porting activities.
The general methodology is the old 'OpenBSD generalise' strategy - when a cross-site bug is found systematically search the code base for other places where that might occur and fix them out.
BGerrison has just pointed out that I need to consider CSS compatibility as well, so lets chuck that in the mix too.
So far all I have come up with for a methodology is:
Are there any structured steps I should take or resources I should be familiar with before I plunge in?
Update
I discovered that the console in Opera 10 kinda lints your css and reports any css typos and stuff...
Javascript
CSS