test-driven-development

Test-driven development prevents regressions by enforcing a strict RED-GREEN-REFACTOR cycle, ensuring every new behavior has a preceding failing test and requiring you to run tests constantly after each phase to catch bugs early.

To implement a new feature using test-driven development, follow the RED-GREEN-REFACTOR cycle: write a failing test for the desired behavior, add the minimal code required to pass the test, and then refactor the implementation safely.

Test-driven development does not require specific testing frameworks, as the methodology focuses on the discipline of writing tests before implementation, running them constantly, and refactoring safely to improve code quality within any agile development process.

The best way to refactor code without breaking existing tests is to follow the test-driven development methodology, ensuring you only refactor after achieving a passing test state and running tests constantly to maintain code quality and prevent regressions.

You should not use test-driven development when exploring rapid prototypes where strict test discipline hinders agility, as this methodology enforces a rigid RED-GREEN-REFACTOR cycle requiring failing tests and constant test runs for every new behavior.