Frontend end testing, what to test and what to use?
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I have been writing tests for my Ruby code for a while, but as a frontend developer I am obviously interested in bring this into the code I write for my frontend code.  There is quite a few different options which I have been playing around with:


- CasperJS - http://casperjs.org/
- Capybara & Rspec - http://railscasts.com/episodes/257-request-specs-and-capybara
- Jamsine - http://pivotal.github.com/jasmine/
- Cucumber Or just Rspec

What are people using for testing?  And further than that what do people test?  Just javascript? links? forms?  hardcoded content?

Any thoughts would be greatly appreciated?