test-driven-development

To enforce test-first development, require a meaningful failing test to be observed before writing any behavior-changing production code, then make minimal changes to satisfy the test. This approach prevents regressions by mandating evidence-based RED to GREEN verification.

The best way to prevent regressions during refactoring is to follow the RED to GREEN to REFACTOR cycle, ensuring you run targeted and broader test suites to verify outcomes. This evidence-driven workflow proves behavior remains correct before and after minimal production changes.

Evidence-driven RED to GREEN verification works by mandating test execution commands at each phase, requiring a failing test first, then confirming it passes after implementation. The completion gate requires concrete command-and-outcome reporting to prove the behavior change is verified.

You need to write failing tests for bug fixes before writing any production code to prove the defect exists and specify the required behavior. This test-first approach ensures the fix targets the exact regression, with mandatory test execution verifying the transition from RED to GREEN.

Yes, test-driven development works across typical codebases and CI test suites by applying targeted then broader verification when feasible. It enforces a completion gate with concrete command-and-outcome reporting, ensuring evidence-based verification for features, bug fixes, and refactors.

The quality bar for unit testing non-trivial changes encourages covering the happy path, failure path, and at least one boundary or edge case. This ensures comprehensive evidence-driven verification before making minimal production changes to satisfy the test.