test-driven-development

Test-driven development (TDD) is a test-first approach where you write a failing test defining expected behavior before implementing minimal production code. This reduces defects, guides software design, and establishes living documentation for future changes.

To start the red-green-refactor cycle, write a failing test that describes the desired behavior, implement the smallest amount of code to make it pass, and then refactor the implementation while keeping the tests green.

Yes, test-driven development applies to bug fixes and refactoring. Writing tests first prevents regressions across software changes, ensures safe refactoring, and enables faster debugging by validating intended behavior before modifying production code.

Writing a failing unit test first ensures the test accurately describes desired behavior and validates the absence of the feature. It drives the software design and guarantees the minimal implementation is correct before proceeding to refactor.

Yes, test-driven development requires no external dependencies. The process relies on the core red-green-refactor cycle to guide feature implementation, making it applicable across typical software projects regardless of specific testing frameworks.