Understanding Unit Tests and Integration Tests
Unit tests and integration tests are both essential components of a comprehensive testing strategy in software development. Each serves a different purpose and operates at different levels of the software.
Exam Question
What are two differences between unit tests and integration tests?
(choose the best two answers)
A. An integration test may be composed of unit tests.
B. A unit test only runs on a Developer’s workstation.
C. An integration test runs overnight.
D. A unit test isolates a specific system behavior.
E. A unit test is automated.
Correct Answers
A. An integration test may be composed of unit tests.
D. A unit test isolates a specific system behavior.
Explanation
Correct Answers
A. An integration test may be composed of unit tests:
Integration tests are designed to verify that different modules or components of a system work together correctly. These tests often build on unit tests by combining them to test the interaction between multiple components. Therefore, integration tests may indeed be composed of several unit tests to ensure that the integrated system functions as expected.
D. A unit test isolates a specific system behavior:
Unit tests focus on testing individual components or functions of a system in isolation. The goal is to verify that a specific part of the code behaves as expected under various conditions. By isolating a particular behavior, unit tests can provide precise feedback on where issues may exist within the codebase.
Why the Other Options Are Less Appropriate
B. A unit test only runs on a Developer’s workstation:
This statement is misleading. While unit tests can be run on a Developer’s workstation, they are not limited to that environment. Unit tests are typically automated and can be run in various environments, including continuous integration servers.
C. An integration test runs overnight:
This is not a defining characteristic of integration tests. While integration tests might be scheduled to run during off-hours (such as overnight), this timing does not distinguish them from unit tests. The key difference lies in what the tests are verifying (individual components vs. integrated systems), not when they run.
E. A unit test is automated:
While it is true that unit tests are often automated, automation is not a unique feature that distinguishes unit tests from integration tests. Both types of tests can be automated.
Relevance to the PSD Exam
Understanding the differences between unit tests and integration tests is essential for the PSD exam. It helps ensure that you can effectively design and implement testing strategies that cover both isolated and integrated components of a system.
Key Takeaways
- Unit tests isolate specific system behaviors to ensure that individual components function correctly.
- Integration tests verify that different components or systems work together as expected and may be composed of unit tests.
- Knowing when and how to apply these tests is crucial for ensuring the overall quality and reliability of software.
Conclusion
Unit tests and integration tests serve distinct but complementary roles in software development. Unit tests isolate specific behaviors, while integration tests ensure that those behaviors work together in a larger context. For more information on preparing for the PSD exam, visit our Professional Scrum Developer PSD™ Exam Prep.
