refactoring-expert

To refactor legacy code safely, you must first establish automated safety nets using characterization tests. This ensures existing behavior is locked down and preserved before you apply any structural transformations or design pattern changes.

Systematically reducing technical debt requires metric-driven, incremental transformations aligned with Fowler's catalog. You apply SOLID principles and DRY cleanup incrementally, using Red-Green-Refactor cycles to guide safer, test-driven improvements.

Applying SOLID principles and design patterns to an existing codebase involves test-driven, incremental refactoring. You identify code smells, scaffold safety nets, and execute pattern-based transformations to improve modularity and testability.

You need characterization tests at the start of a refactoring session on legacy code. They act as safety nets to capture and preserve the current behavior of the module before you begin making incremental design improvements.

This refactoring approach applies to both legacy codebases and ongoing projects needing debt reduction. It guides incremental, test-driven improvements and design pattern application regardless of the project's age.

Test-driven refactoring on code with no test coverage requires building test scaffolding before making changes. This initial characterization testing phase adds upfront effort, but is a necessary limitation to ensure safety nets are established.