moai-workflow-ddd

Behavior-preserving refactoring improves code structure without altering observable functionality. This approach uses AST-grep analysis and characterization tests to ensure complex code transformations remain safe and verifiable.

To refactor legacy code safely, this Skill analyzes the codebase using AST-grep and generates characterization tests to capture current behavior. It guides incremental improvements to reduce technical debt while continuously validating that existing tests pass.

You can extract complex methods into new classes through incremental transformations guided by AST-grep. This Skill identifies high coupling areas and restructures them while using characterization tests to validate that no functional changes occur.

Yes, AST-grep can facilitate API migration scenarios by analyzing existing codebases and guiding behavior-preserving transformations. Characterization tests ensure the API changes do not alter the expected observable functionality.

Characterization tests capture current behavior rather than intended behavior, meaning existing bugs are preserved during refactoring. This Skill relies on continuous validation through these tests, so undocumented or untested edge cases may not be fully protected during transformations.