Fowler Refactoring

Use this skill when code is becoming difficult to change safely and you need to make design improvements without altering external behavior. The material is organized as a task-oriented map into chapter-based resources.

Core mindset (start here every time)

1. Refactor and feature work are separate passes. Pick one hat, do it fully, and do not mix both goals in the same commit.
2. Refactor only to make future change cheaper, clearer, or less error-prone.
3. Stay in a tight safety loop: capture a baseline, apply one small step, and run the relevant checks before moving on.
4. Keep changes local and reversible. Use checkpoints so you can return quickly to the last known-good state.
5. Prefer clarity over cleverness: smaller, well-named units and explicit intent.

Chapter 1 is the baseline mindset anchor: it shows that substantial refactoring is built from small, verified steps.

Decision matrix (fast path)

Use chapter numbers as quick aliases (for example, 3 means Bad Smells, 8 means Moving Features).