Regression testing involves repeatedly evaluating an upgraded web app, software program, or system's existing functionalities as we went through Regression Testing Challenges and Best Practices in a previous post. Testers use it to verify an app's live and new features operate properly. Under regression testing, the quality analyst evaluates current features' functional and non-functional aspects for defects and mistakes.

In a world where technological advances are made on a daily basis, software products are often affected by routine updates. While updating software is necessary for all businesses, it can introduce a slew of bugs into applications and websites. If these software bugs are not thoroughly tested, validated, and fixed, they could end up costing the company a lot of money in production. User interface (UI) and visual bugs in software products are often disregarded due to the focus on functional testing.

Regression testing and unit testing are two different types of testing, yet many of TestQuality users use them interchangeably. Although we already went through Regression Testing Challenges and Best Practices in a previous post, it's important to distinguish between the similarities and differences between regression testing and unit testing. All unit tests are, in essence, regression tests.

The testing landscape has changed over time to include automated and functional testing as the baseline, but there are still ways to improve your testing because even with a fully automated continuous testing pipeline, there can still be the possibility of bugs existing in your passing tests. One of the ways to mitigate this is by adding visual testing to your testing pipeline.

Automated visual regression testing tools check for style issues and problems with the visual layer of an app or website. The benefit of these tools is that they can catch issues on the visual layer (the user interface of the website or app, which customers see) that may get missed by test scripts that only interact with the underlying code (the DOM).

For teams following agile software development practices, regression testing is a must. Agile teams constantly make changes to live software that can introduce regressions (or, code changes that break the functionality of part of an app). Regression testing can keep teams from shipping critical bugs to production by confirming the most important parts of an app are still working every time new code is pushed.

Regression Testing, as all Quality Assurance professionals know, is ensuring that previously developed and tested software continues to operate after a change. Performance Regression being a subset of regression testing as a discipline is therefore ensuring that previously developed and tested continues to meet its performance criteria after a change.