The article is not about refactoring. It's about rewriting the software. So that's why I didn't mention about refactoring in details. Automated testing is part

The article is not about refactoring. It's about rewriting the software. So that's why I didn't mention about refactoring in details. Automated testing is part of the refactoring. You will change a small amount of code then run tests to see it works as expected. This is how refactoring works. No need to mention abou that.