Regression Testing is a type of software testing used to confirm that recent code changes have not negatively impacted existing functionality. It is essential in continuous software development environments where new features, bug fixes, and improvements are frequently added. By retesting existing functions and workflows after each change, regression testing ensures that modifications do not introduce unintended issues or “regressions” in the software.

The process of regression testing typically includes the following steps:

Selecting Test Cases: Test cases relevant to areas impacted by the code changes are chosen. Automated tests are commonly used, as they can run quickly and cover a broad range of functions.
Automated and Manual Testing: While automated tests are efficient for regression testing, manual testing may still be used for complex workflows or edge cases that automation cannot easily replicate.
Testing All Layers: Regression testing often covers unit, integration, and end-to-end tests, ensuring functionality remains intact at all levels.
Result Analysis: Any failures in regression tests are investigated and logged, often indicating areas that require additional debugging.
Regression testing is especially valuable in Agile and DevOps methodologies where frequent deployments are the norm. Automated regression suites run as part of CI/CD pipelines to verify that code changes meet quality standards before reaching production. By maintaining a stable product with high confidence, regression testing helps prevent the reintroduction of resolved issues, enhancing the user experience.

Regression testing is critical for businesses that prioritize quality, reliability, and user satisfaction. As codebases evolve, regression testing is a key strategy to avoid setbacks, maintain trust, and ensure smooth functionality across software releases.