refactor-test-safety-net

[Code Quality] Establishes test coverage requirements before refactoring. Use to identify missing tests, create minimal safety net tests, and define verification strategy for behavior preservation.

Refactor: Test Safety Net

Ensure adequate test coverage before making changes.

Pre-Refactoring Test Checklist

1. Coverage Assessment

What's the current test coverage?
Which paths are untested?

2. Test Types Needed

| Type | Purpose | When Required | |------|---------|---------------| | Unit | Function behavior | Always | | Integration | Component interaction | Cross-module changes | | Snapshot | UI/Output structure | View refactoring | | Regression | Known bug prevention | Bug-prone areas |

3. Minimal Safety Net

Priority 1: Happy path test Priority 2: Error handling test Priority 3: Edge case test

Rules

Never refactor without tests on the target code
Add tests BEFORE changes, not after
Characterization tests capture behavior, not correctness
Run tests after each small step