midUnit Testing
What is test-driven development (TDD)?
Updated May 6, 2026
Short answer
TDD is writing tests before writing production code.
Deep explanation
TDD follows Red-Green-Refactor cycle: write failing test, implement code, refactor. It improves design and ensures test coverage.
Real-world example
Building APIs with tests defined before implementation.
Common mistakes
- Skipping refactoring phase.
Follow-up questions
- Benefits of TDD?
- Is TDD always necessary?