test-driven-development

Test-driven development prevents bugs by enforcing a rigorous Red-Green-Refactor cycle, requiring a failing test before any production code is written to catch regressions early. This guarantees code reliability throughout development.

To apply the Red-Green-Refactor cycle, first write a failing test for the new functionality, then write minimal production code to make it pass, and finally refactor the code for quality. This ensures every feature has test coverage.

The best way to start TDD for user authentication is to write a failing test for a successful login scenario first. Once the test fails, write the minimal authentication code required to pass it, then refactor.

Yes, you can use test-driven development for refactoring efforts. The workflow applies to refactoring by ensuring you write or verify failing tests first, make minimal code changes to pass them, and then safely improve the structure.

You should not use test-driven development when exploring experimental code spikes or building throwaway prototypes where immediate reliability and regression prevention are not required. TDD is designed for committed production code.