- Test-Driven Development: By Example - Kent Beck - 2002 - TDD from the inventor of TDD — walks through the process step by step with real code.
- Growing Object-Oriented Software, Guided by Tests - Freeman & Pryce - 2009 - The best book on TDD in practice, showing how tests shape real architecture.
- The Art of Unit Testing, 3rd Ed. - Roy Osherove - 2019 - Practical patterns for writing tests that are maintainable and trustworthy.
- Software Engineering at Google - Winters, Manshreck, Wright - 2020 - How Google thinks about testing, code review, maintainability, and scale — free online.
- xUnit Test Patterns - Gerard Meszaros - 2007 - Refactoring test code and test patterns; the testing classic.