Refactoring Real-World Code

A deliberately messy order-pricing service alongside a behavior-preserving refactor. The repo is designed for reviewers to compare implementations and see why each change matters.

Portfolio signal

• Demonstrates how to refactor under characterization tests instead of rewriting by instinct.
• Preserves behavior while introducing a clearer domain model and service boundary.
• Documents the progression so reviewers can judge the engineering decisions, not just the final code.

What to review

• src/refactor_case/legacy.py for the starting point.
• src/refactor_case/service.py and src/refactor_case/domain.py for the refactor.
• REFACTORING_NOTES.md for the reasoning trail.

Quick start

pip install -e .[dev]
pytest -q

Refactoring progression

v0-legacy → characterization tests → domain model → strategy extraction → explicit validation → production-oriented service boundary. See REFACTORING_NOTES.md.