What type of testing ensures previously working features are not affected by new updates?

Regression testing is a critical process in software development and maintenance, particularly when it comes to ensuring that new updates or changes do not negatively impact existing functionality. This type of testing involves re-executing previously completed tests on the updated software to verify that existing features still perform as expected after a change, such as a software update, bug fix, or new feature addition.

In the context of cloud systems like the Ericsson Cloud RAN, where frequent updates may be applied to enhance performance, fix issues, or introduce new capabilities, regression testing serves as a safeguard. This ensures that even as the system evolves, the core functionalities that users rely on remain stable and intact. By identifying any faults that may arise due to the introduction of new code, regression testing helps maintain the integrity and reliability of the system, which is essential for user satisfaction and operational efficiency.

Understanding regression testing is vital for anyone involved in Quality Assurance and software development, as it reinforces the importance of maintaining existing functionality during the iterative process of software enhancement and fixes.