Testing after each change means that when I make a mistake, I only have a small change to consider in order to spot the error, which makes it far easier to find and fix.
[...]
I confess I don’t always take quite as short steps as these—but whenever things get difficult, my first reaction is to take shorter steps.
— 📖 Refactoring﹕ Improving the Design
- context: Fowler's very small-stepped process of going through a refactor