refactor-safely

To safely refactor legacy code, you make small, incremental changes while enforcing test presence and running regression validation to ensure external behavior remains unchanged before committing.

Incremental refactoring is a technique that improves code structure in small, isolated steps with explicit scope. You need it when modifying legacy codebases to maintain readability without altering external behavior or breaking API contracts.

When refactoring code lacking test coverage, you add tests as a safety net before making structural changes. This risk-aware planning ensures behavior-preserving validation and allows you to verify each step.

Incremental refactoring targets small, isolated scope changes rather than large modules. It works by identifying a minimal scope, adding tests if needed, and performing a single-step refactor to maintain safety.

The best way to document refactoring steps is by creating checkpoints with a clear rollback plan for each change. This risk-aware approach ensures an auditable git history and predictable behavior preservation.