I write a lot of tests and I've tried this a lot of times (since it can be done with any test framework plus a file watcher on any language) but it doesn't help on my workflow.
The integration with the code editor looks nice as long as it has a way to "jump to the first broken test", and show all the details of the error. I remember when I used to work on c# the test runner of resharper integrated and it was great. My current workflow is, I run the tests in the console and if some test is broken, I search the name of the test across the project to inspect.
Parallel test execution in javascript hasn't worked for me, most of the time I depend on some "state" call it DOM (browser), or call it a test database (node). The fact that I can assume that the runner run one test at the time makes my tests and the before/after code simpler.