refactoring-code

Safe refactoring restructures code while preserving behavior by using dependency analysis tools to trace all symbol usages, running tests before and after each change, and applying incremental steps like extract method and rename. Serena safe refactoring tools ensure all callers are identified and updated correctly.

Extract method refactoring divides large functions into smaller, focused methods while maintaining test coverage. Use find_referencing_symbols to identify all callers, perform incremental extractions with tests passing between steps, and verify usages prior to changes to ensure nothing breaks.

Dead code removal uses find_symbol and find_referencing_symbols to verify no active code depends on unused functions or variables. Once you confirm zero references, remove the dead code incrementally and run tests to validate the change doesn't affect system behavior.

Yes, rename refactoring safely updates all symbol references when you use Serena's rename_symbol tool, which traces every caller automatically. Run tests before and after the rename to confirm behavior remains unchanged across your codebase.

Refactor when code is hard to read, modify, or test but its behavior is correct and well-tested. Refactoring preserves existing functionality through small, verified steps, while rewriting risks introducing bugs. Use refactoring for maintainability improvements without feature changes.

Yes, tests must be green before refactoring begins; they verify behavior doesn't change during restructuring. Refactoring separates from feature work—keep tests passing after each incremental step to catch regressions immediately.