This week I decided to add a new element to a javascript array by copying a similar one from a previous line; unfortunately I forgot to remove the comma so the end result was something like var a = [1, 2, 3,].

The code went live late Friday afternoon just before everyone left for the week-end, and it completely broke everything in Internet Explorer 7 (and lower I assume) since it's such a great browser. Since there was no one to read emails (week-end) it went unnoticed for quite a while, and I really don't want something like this to happen again (especially in my code)..

This is not the first of weird IE7 problems; I was wondering if there was a way to automatically test key pages looking for javascript or css errors, or really anything that IE8 would output in its new console in development tools.

If there isn't, what do you usually do? You test the website after every change with all the browsers you support? (Something I'll do from now, at least for IE, if there is no way to run automated tests)