Increasing Code Testability

Code testability refers to how easily and effectively a piece of code can be tested. Certain practices and models significantly improve testability by ensuring that code is consistently integrated, tested, and maintained.

Exam Question

Which model or idea increases code testability?
(choose the best answer)
A. INVEST (Independent, Negotiable, Valuable, Estimable, Small Enough, Testable)
B. CI (Continuous Integration)
C. SOLID (Single responsibility, Open-closed, Liskov substitution, Interface segregation, and Dependency Inversion)
D. PLP (Principle of Least Privilege)

Correct Answer

B. CI (Continuous Integration)

Explanation

Correct Answer

B. CI (Continuous Integration):
Continuous Integration (CI) is a practice in software development where code changes are automatically tested and integrated into a shared repository frequently, often several times a day. CI directly increases code testability by ensuring that:

• Code is consistently and regularly tested, catching issues early in the development process.
• Developers are encouraged to write automated tests as part of their development workflow, making it easier to identify problems.
• Integrating code changes frequently reduces the complexity of integrating large changes, which can complicate testing and debugging.

By continuously integrating and testing code, CI helps maintain a high level of code quality and ensures that any issues are identified and addressed promptly, thereby improving the overall testability of the code.

Why the Other Options Are Less Focused on Testability

A. INVEST (Independent, Negotiable, Valuable, Estimable, Small Enough, Testable):
INVEST criteria are used for writing user stories in Agile development. While “Testable” is one of the criteria, INVEST is focused on the quality of user stories rather than directly impacting code testability.

C. SOLID (Single responsibility, Open-closed, Liskov substitution, Interface segregation, and Dependency Inversion):
SOLID principles are crucial for writing maintainable and modular code, which can indirectly improve testability. However, CI directly impacts the process of testing and integrating code, making it a more direct factor in increasing code testability.

D. PLP (Principle of Least Privilege):
The Principle of Least Privilege is a security principle that focuses on minimizing access levels. While important for security, it does not directly influence the testability of code.

Relevance to the PSD Exam

Understanding the role of Continuous Integration in increasing code testability is important for the PSD exam. It emphasizes the importance of regular testing and integration in maintaining code quality and ensuring that code remains testable throughout the development process.

Key Takeaways

• Continuous Integration (CI) plays a crucial role in increasing code testability by ensuring that code is consistently tested and integrated.
• CI helps identify issues early, reduces integration complexity, and encourages the development of automated tests.
• Other concepts like SOLID and INVEST are important for code quality and Agile practices, but CI directly impacts the process of testing and integrating code.

Conclusion

Continuous Integration is a key practice that directly increases code testability by ensuring that code changes are frequently tested and integrated. Understanding the importance of CI is essential for maintaining high code quality and ensuring that issues are identified early in the development process. For more information on preparing for the PSD exam, visit our Professional Scrum Developer PSD™ Exam Prep.