test-driven-development

Test-driven development prevents regressions by enforcing a test-first workflow where you write failing tests before production code, clarifying requirements and guarding existing behavior against future changes.

To apply the red-green-refactor cycle, write a failing unit test specifying intended behavior, implement minimal production code to pass the test, then refactor the codebase iteratively while maintaining test safety.

You need an existing test harness or framework capable of generating and running failing tests before implementation, but no specific framework is mandated as long as it supports test-first execution.

The best way to start writing tests for bug fixes is to write a failing unit test that reproduces the reported bug, specifying the expected correct behavior before modifying any production code.

Yes, test-driven development supports refactoring across existing codebases and team workflows by ensuring incremental progress and providing a safety net of unit tests that verify expected behavior remains intact.

Writing failing tests before implementing minimal production code clarifies software requirements upfront, improves documentation of expected behavior, and drives design decisions through the test-first workflow.