Run tests on file change

I there any way to automatically run a project's tests (or a subset thereof) when a source file changes. Something like but built into the Rust tools?

I don’t think this needs to be integrated into Cargo or rustc. On Linux it’s easy to make a small script based on inotify that runs any command you give it when something changes in a directory. OS X has something similar, though I don’t remember what it’s called.

Thanks for the information.