Test-Driven Development in Practice

Test-Driven Development is not just a testing technique—it is a discipline that fundamentally changes how you design software. By writing tests before code, you clarify requirements, decouple components, and catch bugs early. In this ten-article series, you will learn to practice TDD at every level: unit tests, integration tests, and legacy code refactoring. You'll discover the philosophical differences between classicist and mockist testing styles, master outside-in TDD for feature development, and recognize anti-patterns that undermine your test suite. Each article pairs theory with runnable C# examples so you can apply these practices immediately.

Articles in this series

1. TDD C#: Red-Green-Refactor Cycle Explained
2. Unit Testing C#: Write Tests Before Code
3. Test-Driven Development: Classicist vs Mockist Styles
4. Outside-In TDD: Building Features Test-First
5. Mocking in C#: xUnit vs Moq Best Practices
6. TDD for Legacy Code: Refactoring with Tests
7. Test-Driven Design: API-First Development in C#
8. Integration Testing TDD: Database and I/O
9. Property-Based Testing C#: QuickCheck Patterns
10. TDD Anti-Patterns: Common Mistakes and Fixes