refactoring

To refactor legacy code without changing behavior, identify code smells like long functions and duplicated code, then apply an incremental refactor with test verification and small commits to preserve observable behavior.

Common code smells include long functions, large classes, and duplicated code. Fix them safely through a planned, incremental refactor that verifies tests after each change to preserve original behavior.

Reduce code complexity by identifying maintainability issues like large classes and long functions, then executing a safe incremental refactor with test verification and clear rollback guidelines.

The best way to plan an incremental refactor for large modules is to detect specific code smells, then execute small commits with continuous test verification to ensure behavior-preserving clean-up.

Tests are required before starting a safe refactoring workflow to verify that changes preserve observable behavior, enabling small commits and clear rollback guidelines throughout the incremental process.

Incremental refactoring improves readability and maintainability through behavior-preserving changes with test verification, whereas rewriting risks introducing bugs and losing original functionality.