I could see something like this being extremely useful when working with legacy code. In the book "Continuous Delivery (Humble, Farley)" they suggest when work

I could see something like this being extremely useful when working with legacy code. In the book "Continuous Delivery (Humble, Farley)" they suggest when working in legacy code without tests, to begin adding testing to systems starting only with the parts you changed. If this is hard to determine, a test feature that shows unit dependencies could be really helpful.