refactor

Test-first refactoring prevents regressions by auditing existing test coverage and generating characterization tests for uncovered logic before applying any structural or API improvements to your code.

Improving code quality in a complex Python module is best handled by enforcing a test-first refactoring workflow, which documents all current behaviors with characterization tests first, and then incrementally applies logic improvements while verifying each step against the test suite.

You generate characterization tests for uncovered code by running an automated test coverage audit that identifies missing tests and creates them to document current input/output behaviors, ensuring a safe baseline before any logic changes are applied.

Yes, test-first refactoring can orchestrate code improvements across single files, entire directories, or modules by systematically ensuring test coverage exists and verifying consistency across all targeted code before applying structural changes.

You do not need existing test coverage to start refactoring, because this approach automatically checks for tests and generates characterization tests for uncovered code to establish a behavioral baseline before applying any logic improvements.