Google built a testing system that can infer which tests need to be run after a change. In their own words:
... we built a continuous integration system that uses dependency analysis to determine all the tests a change transitively affects and then runs only those tests for every change.
Inspired by that, I have created a tool for Python that also uses dependency analysis to detect which tests need to be run. The difference is that it is not tied to a CI system. It is meant to be run locally and looks for file changes since the last time the tests passed, instead of looking at commits on the version control system.
Visual Studio 2010 has a featured called "Test impact analysis" that "inform the developer of what tests they should run to verify the code changes they are making".
My question is: Is there a name for this approach? I believe I read somewhere that this is called "Incremental Testing", but I cannot find the reference anymore.