test-driven-development

Test-driven development reduces defects by requiring a failing test to define expected behavior before any implementation. This enforces a red-green-refactor cycle, ensuring minimal production code passes tests and validates behavior through automated tests.

The red-green-refactor cycle in TDD is a workflow where you first write a failing test to define behavior, then implement minimal production code to pass it, and finally refactor while keeping tests green to ensure code correctness.

To use TDD for bug fixes and refactoring, write a failing test that reproduces the bug or verifies the new behavior, implement minimal code to pass the test, and refactor safely using automated tests to prevent regressions.

Yes, you can apply test-driven development across software projects for feature development, bug fixes, refactoring, and behavior changes. It forces test-first development to ensure robust code regardless of the specific software engineering context.

You should avoid test-driven development when writing exploratory code or throwaway scripts where validating behavior through automated tests is unnecessary overhead, as TDD enforces minimal production code that passes tests strictly.