I'm not quite sure about your deployment requirements without a browser without a browser, but my team uses it phantomjswith jasminericegem to automate our testing of JavaScript on a mute browser with WebKit.
JRuby 1.6.7 Rails 3.2.3. CoffeeScript, Rails CoffeeScript JavaScript, jasminerice. , , JavaScript.
, , , , , quick guide (gist on Github), :
, , jasminerice phantomjs CoffeeScript Win/JRuby. , !