I definitely second being able to write plugins for running tests, especially for JS. I appreciate it might be difficult for other languages, but I think it could still be done. I've managed to work out a system where I have an NUnit test fixture which starts a self-hosted web server on a specific port, then fires up karma and PhantomJS to run Jasmine tests which connect to the web server so we can have full end-to-end testing, then I use NUnit's TestCaseSource to parse the result file into distinct tests which get displayed individually in NCrunch.
It works OK, but it's pretty convoluted and clunky. The JS tests get run automatically by NCrunch now, but they take a good 10 seconds to run (most of which is spent spinning up PhantomJS each time), there's no code coverage, they don't properly pick up changes all the time, it can't automatically take you to the point of failure, etc. The case above is especially convoluted because I want to run the web server for the JS tests to connect to. In the more general case, I'd love to just be able to keep the karma runner going in the background, which runs the tests continuously anyway as I change JS files in my solution, then have NCrunch pick up some output file that gets updated frequently, or send results to it as they happen or something.
