In the context of testing, what enables the developer to identify broken functionality after a code change?

Regression testing is a crucial practice that enables developers to identify broken functionality after any code changes have been made. The primary purpose of regression testing is to ensure that new code modifications do not adversely affect the existing functionality of the application. This is particularly important in environments where software is continuously updated or modified, as even small changes to the code can lead to unexpected issues or bugs in previously functioning features.

By running a set of previously conducted tests, regression testing can highlight deviations from the expected behavior of the software, allowing developers to catch issues early in the development process. This practice helps in maintaining software quality, ensuring that recent updates or fixes do not reintroduce old defects or create new ones in the existing codebase.

Unit tests focus on individual components or functions but do not typically assess the interaction of these components with the broader system. Integration tests check how various modules work together, but they may not comprehensively verify that existing features remain functional after changes. System tests evaluate the entire system's compliance with the specified requirements but may not specifically target the broken functionality aspect after code alterations. Overall, regression testing is the most effective approach for monitoring the stability and integrity of the software following changes.