test-driven-development

Test-driven development starts by writing a failing test that defines expected behavior for a new feature. You then write the minimal production code required to make that test pass, ensuring the feature works correctly from the outset.

The Red-Green-Refactor cycle is the core TDD process where you write a failing test, write minimal code to make it pass, and then clean up the code. This iterative cycle ensures verifiable, maintainable code and prevents regressions.

You should use test-first development when starting a new feature to clarify requirements and ensure robust, verifiable code. By mandating tests before implementation, it prevents regressions and guides you through the Red-Green-Refactor cycle.

Test-driven development supports refactoring by ensuring all production code is preceded by a failing test. After making tests pass, you can safely clean up code within the Red-Green-Refactor cycle without introducing regressions.

Preventing code regressions in agile development is best achieved through test-driven development. By enforcing a test-first methodology and the Red-Green-Refactor cycle, it ensures all production code is verifiable and maintainable.

Writing failing tests before production code clarifies expected behavior and ensures the feature meets requirements from the outset. This test-first approach guarantees your code is robust, verifiable, and maintainable by preventing regressions.