refactor

To plan a safe code refactor, decompose the target into behavior-preserving tiny commits with pre-flight checks and characterization tests. This approach emphasizes a clean working tree and commit-by-commit verification to ensure behavior remains unchanged throughout the process.

Seams and ports-adapters in refactoring are interface boundaries that improve module testability and locality of change. By restructuring code around these boundaries, you increase leverage at the interface and isolate dependencies for safer, more verifiable modifications.

To find refactoring opportunities in an existing codebase, scan for shallow modules that lack leverage. Identify where introducing seams or adapters would improve testability and increase locality of change, allowing for safer restructuring without adding new features.

Break down a large module refactor by scoping the target and decomposing it into tiny, testable commits. Document interface and seam decisions while running characterization tests between commits to verify behavior preservation at each step of the restructuring process.

Yes, you can use this refactoring approach with low test coverage by writing characterization tests before starting. The safety-first planning method identifies thin coverage during pre-flight checks and prioritizes establishing verification tests before making structural changes.

You should avoid restructuring modules for testability when the work involves introducing new features alongside structural changes. Safe refactoring requires strict scope control to separate behavior preservation from feature development, ensuring modifications remain verifiable and controlled.