This is why jQuery exists. Honestly I can't imagine using TDD for any kind of Web project. It costs money to use it in the form of time and the margins just aren't there. The problem with a lot of software development methods is that that kind of process costs money and in the low risk fast changing Web world, those dollars are better spent on another developer, or more expensive developers, that can build shit right and get it through a QA session pretty quickly.
The truth is mainly non-Academic methods of build Webware (I made that up, no you can't use it) just aren't viable. Not because they aren't good ideas or work...but because they cost money up-front and so often there isn't another dev cycle on a project that isn't trivial or requires that great planning was made. Especially on the front end.
Patterns are more important than practices.