The Role of a Test in Test-Driven Development (TDD)

Test-Driven Development (TDD) is a development practice where tests are written before the actual code. These tests serve as a guide for the development process, ensuring that the code meets the specified requirements and behaves as expected.

Exam Question

What does a test written in Test-Driven Development represent?
(choose the best answer)
A. Something that completes the test coverage of a system.
B. A technical requirement that must be satisfied.
C. A bug that will be uncovered.
D. An assignment from the lead quality engineer.

Correct Answer

B. A technical requirement that must be satisfied.

Explanation

Correct Answer

B. A technical requirement that must be satisfied:
In Test-Driven Development, each test represents a specific technical requirement or behavior that the system must fulfill. The process of writing a test before the code ensures that the code is developed to meet these requirements. The test serves as a specification that defines how the system should behave under certain conditions. Once the test is written, the developer then writes the minimum amount of code necessary to make the test pass, ensuring that the technical requirement is met.

Why the Other Options Are Less Appropriate

A. Something that completes the test coverage of a system:
While TDD helps in building comprehensive test coverage over time, the primary purpose of each test is to represent a specific requirement or behavior, not just to increase coverage. Coverage is a byproduct, not the primary goal.

C. A bug that will be uncovered:
TDD tests are written to define expected behaviors, not necessarily to uncover existing bugs. While tests might expose bugs, their primary purpose is to define and ensure that the code meets specified requirements.

D. An assignment from the lead quality engineer:
In TDD, tests are typically written by the developers themselves as part of the development process, rather than being assigned by a lead quality engineer. The tests define the functionality that the developers intend to implement.

Relevance to the PSD Exam

Understanding the purpose of a test in TDD is crucial for the PSD exam, as it emphasizes the role of tests in guiding the development process and ensuring that technical requirements are met.

Key Takeaways

• TDD tests represent technical requirements or behaviors that the code must satisfy.
• The primary purpose of TDD is to define expected behaviors and ensure the code meets these specifications.
• Test coverage is a secondary benefit of TDD, not the primary purpose of the tests.

Conclusion

In Test-Driven Development, a test represents a technical requirement that must be satisfied. This approach ensures that the code is developed with clear goals and meets the specified behaviors. For more information on preparing for the PSD exam, visit our Professional Scrum Developer PSD™ Exam Prep.