Generally I like refactoring. Essentially, it is the process of taking disjoint, complicated code and making simpler and logically consistent. I have never real

Generally I like refactoring. Essentially, it is the process of taking disjoint, complicated code and making simpler and logically consistent. I have never really though of refactoring as something to fear until I'd spent time working in a Node shop. You don't want to stop and fix "unrelated" errors, but if B was broken by a type change in A then it is almost certain that B is affected by the changes in A. Right now, when you are making the changes in A, is the best time to address the fallout, because you have the reason for the change and all its subtleties in mind. The vast majority of the bugs my team addressed after our last major refactor in our Node codebase were of this kind: either completely forgotten or unknown components affected, or fixes that were not fully aware of the changes made. Knowing at the time of the change all of the places that change affects is extremely powerful. Tests only get you this for the easy cases you've thought of. Static typing doesn't get you that entirely, but it gets you a lot closer than dynamic typing. So I'd argue the opposite. Dynamic languages taught me to fear refactoring because they're is always the danger that you missed something buried somewhere that will come back to bite you in really subtle ways. I never get the satisfying feeling of unifying the code under a new logical consistency because there may still be these loose ends lurking around.