I can't help you with static checking, but if you'd like a little runtime pre- and post-condition checking for JavaScript... https://github.com/raganwald/metho

I can't help you with static checking, but if you'd like a little runtime pre- and post-condition checking for JavaScript... https://github.com/raganwald/method-combinators/blob/master/lib/method-combinators.js https://github.com/raganwald/method-combinators/blob/master/...