Understanding the differences between regression testing and unit testing is paramount for maintaining the robustness of any software. Although both serve the purpose of vulnerability scanning to detect threats, they vary in terms of their test objectives, stages in the development process, and the scope of the code they cover. Let's delve into these distinctions to grasp their roles better. Difference in Test Objectives: - While similar, Unit and regression testing have distinct targets within your code. Unit testing, conducted by programmers, assesses individual components, validating the correct functionality of each variable, function, and object. - On the other hand, regression testing (often termed QA testing) occurs after programmers complete work on specific features. It acts as a system-wide check, ensuring untouched components function as expected. While unit tests provide the precision of individual functions and variables, regression tests collaborate to ascertain that the entire system functions optimally. Difference in the Development Phase: - The timing of unit and regression tests sets them apart. Unit tests are conducted during the development phase, where developers run them after implementing changes to confirm no adverse impacts. - Conversely, regression testing is performed before the feature's production release. It comprises unit tests, integration tests, and various other testing types. Testers are responsible for executing regression testing. Automated regression testing, a key step in continuous integration/continuous delivery, quickly detects if recent code changes have disrupted the existing code. Difference in Code Coverage: - A unit test concentrates on a single unit, method, or function, examining one element at a time. It doesn't account for how these units interact, necessitating integration tests. This approach provides swift feedback due to its focused testing nature. - In contrast, regression tests validate if alterations to existing functionalities have affected other parts of the system by testing against predefined scenarios, ensuring correct integration of units. Given the comprehensive testing involved, it generally consumes more time. Unit and regression testing are vital pillars in the software development journey. Regular execution of these tests is key to minimizing bugs and refining code quality. Regression testing conducted post-unit testing before a software release, ensures system integrity despite changes. On the other hand, unit testing meticulously validates new functions, ensuring precise code execution.