Certified Associate in Software Testing (CAST) Practice Test

What is the core purpose of unit testing?

1. To validate integration of components

2. To conduct performance testing

3. To test individual programs or components

4. To ensure overall system functioning

The correct answer is: To test individual programs or components

Unit testing is primarily focused on verifying the functionality of individual programs or components within a software application. The core purpose of this type of testing is to isolate each unit and confirm that it behaves as expected, adhering to specified requirements and design. This allows developers to detect issues at an early stage, ensuring that each part of the program works correctly before they are integrated into larger systems. By concentrating on small, discrete pieces of code, unit testing facilitates easier debugging and enhances overall code quality. It specifically targets the logic of the unit being tested, ensuring that the code performs its designated tasks effectively. This prevents defects that might propagate to later integration or system-level testing phases, where they could become more complex and costly to resolve. Other approaches like validating integration of components, conducting performance testing, or ensuring overall system functioning are broader in scope. They focus on how units work together, measure the system's responsiveness or resource usage, and evaluate the application as a whole. While these are essential aspects of a comprehensive testing strategy, they do not capture the specific goal of unit testing, which is to ensure the correctness of individual components before they interact with one another.