Tellurium is a JavaScript Testing Framework using testing patterns like Mock, Stub, and Spy.
this framework tries to go as close as possible with EcmaScript behaviour. so if you used anothers language
testing frameworks you may find that some of your tools are not here but trust me its better this way.

you still can extend the framework so easy, it was written in a couple of days, actually testing it with itself was the hardest part, so you should be able to extend it easily.