2. React refactorings
3. Redux refactorings
4. Other refactorings
R-Factor has been thoroughly tested. We have 100% test coverage. Every statement, every branch, every function & every line is covered. 836 test cases, all green! We have run this tool on over 20 different projects with different settings. We've gathered feedback from a few independent developers. It's still just software, but we feel we did pretty damn good.
It's worth noting that not once have we experienced performance issues.
One of our testers after using R-Factor