test-preserving-refactorlisted

## Purpose Refactoring is only safe if it is backed by tests. Work in a strict loop — green baseline, one structural change, immediate re-run, revert on red — so you are never trapped in an uncompilable state. ## When to Use - Code needs restructuring (extract/inline/move) without behavior change - A previous refactor spiraled into a broken, hard-to-recover state - Tests covering the target area exist or can be run ## Inputs - The target area and the command that runs just its tests ## Workflow 1. **Run tests first.** Before touching any code, run the tests covering the target area. They MUST be green. If they are red, stop and fix the tests (or the code) first: ```bash npx jest path/to/target # or: pytest tests/test_target.py -q ``` 2. **Small steps.** Make one structural change at a time (e.g., extract a method). 3. **Run tests immediately** after the single structural change. The per-change loop: ```bash # repeat per structural change: edit -> test -> commit (green) | revert (red) npx jest path/to/target && git commit -am "refactor: extract X" || git checkout -- . ``` 4. **Revert on red.** If the tests fail, you made a mistake. Revert the change (`git checkout -- .` or `git restore .`) and try a different approach. Do not attempt to "fix" the refactor while tests are failing. 5. **Commit on green.** Once the small change is green, consider it a safe checkpoint. This strict loop prevents you from getting trapped in an uncompilabl