It is often useful to

a) automatically run tests, or
b) automatically restart a service

whenever the code changes. Service-runner would be a great place to add such functionality, to be enabled with commandline parameters (--auto-test and --auto-service-restart?).

There are quite a few existing tools in this area, so adding a feature like this might be very simple:

• native [fs.watch](http://nodejs.org/api/fs.html#fs_fs_watch_filename_options_listener)
• https://github.com/remy/nodemon
• <your favorite one here>