What is Regression Testing: Definition, Importance, and Best Practices

The iterative and continuous DevOps approach to software is like stacking blocks. It’s a balancing act. With each change or update, your team adds another block to the tower. If the new block isn’t placed correctly or shaped correctly, in other words, developed and tested for compatibility with the larger system, the whole tower can come crashing down. This analogy explains the need for Regression Testing.

Without Regression Testing, there’s no way for your team to ensure that a new build isn’t going to break a feature added in a previous version. So when that new build gets pushed to production, chaos suddenly breaks loose, and your team isn’t prepared.

Your user base can fall back to your Instatus status pages for updates about when a fix is expected. But that is not an ideal situation, and a bit of foresight and Regression Testing can often prevent these outcomes.

What is Regression Testing?

Regression testing is a form of testing to ensure that a new update or rollout hasn’t introduced any bugs or broken any existing functionality. Regression indicates your application has regressed to a previous state in development. Essentially, issues your team has already addressed or functionality your team worked so hard to implement are now broken because of a new feature.

Regression effects often result from unexpected interactions within the codebase that developers didn’t anticipate. Regression Testing catches bugs introduced by a new build before reaching production, so your team can reduce incidents and outages. Areas that have previously been tested are now retested. Regression Testing is not the same as traditional retesting, in which a test case is rerun to ensure an issue has been successfully fixed.

The Importance of Regression Testing

By reducing incidents, your team effectively limits over-reliance on support systems like Instatus status pages. Status pages are a buffer when your team is busy scrambling to handle a system failure or critical outage.

With Instatus, your team can set up an elegant and modern landing page for your user base to check for updates when your application is experiencing issues. But as a DevOps team, your goal is to limit these events (and reduce change failure rate) through careful planning, development, and testing.

High uptime rates are great for user base retention and preserving your application’s reputation as a quality software product. Ideally, your organization wants that 99.9% uptime displayed on Instatus. Regression Testing will help your team get there.

Regression Testing vs Other Forms of Testing

Regression Testing is a bit different than other established forms of software testing like White Box Testing, Black Box Testing, and Exploratory Testing. For one, it’s not as original as the other forms. Regression Testing usually builds upon existing test cases, with a few possible additions.

Any new updates or added features will undergo their own testing cycle, independent of regression testing. Only after that testing is complete will the rest of the application undergo Regression Testing. Regression Testing is kind of the easiest part of the testing cycle because your team doesn’t need to build many new test cases, so there’s really no reason to skip it.

Performing Regression Testing

Regression Testing Best Practices

So, where should your QA team begin when adding Regression Testing to your testing cycle? It’s very complex as long as you follow a few key best practices:

1. Automate!

With Regression Testing, your team reuses previously written test cases from earlier software versions. If 100 test cases were written for version 1.0.5 and 100 for 1.0.6, then by 1.0.7, that means 200+ test cases within just the last two versions. You can see how this would quickly get out of hand and become impossible for your QA team to carry out this number of tests manually.

Your best bet when employing Regression Testing is to automate your testing suite. With each new build, you will return to the same test cases over and over again, adding new test cases each time. By automating the testing process, you can pass your application through the tests your developers and QA tests have worked diligently to write without any significant issues or time commitment.

2. Update Regression Test Suite

It’s crucial to keep your Regression Test suite updated. As soon as a build is released, the testing phase is complete. That build will have its own set of test cases from the following forms of testing:

• White Box Testing
• Black Box Testing
• Exploratory Testing

All of these test cases should be added to the Regression Test suite to be ready for testing in the next build. Keeping with this workflow keeps the process smooth and manageable and prevents your team from accidentally missing a set of tests that might reveal a critical bug.

Eventually, your team can remove outdated test cases to keep the testing suite manageable.

3. Prioritize Testing

Ideally, your team should further organize the Regression Test suite by priority. Any tests that verify the functionality and security of critical conditions should be prioritized over less critical conditions.

Your QA team should run these test cases first to flag any critical issues as soon as possible. Your development team can immediately start fixing the critical problems while the Regression Test suite finishes.

Summarizing Regression Testing

Regression Testing is the final step in the DevOps testing process, intended to ensure your application isn’t ‘regressing’ to a previous state with broken features. Remember that syncing feature your developers worked super hard to implement a few builds ago? We’ll your team didn’t use regression testing, so now that feature is broken, and your developers have to work on the fly to solve the problem and roll out a fix.

That series of events, where the tower topples unexpectedly, is avoidable using Regression Testing. While your Instatus page is there to update your user base in the case of an incident or outage, your team doesn’t actually want users ever to have to report there! With thorough Regression Testing using an updated test suite and automated testing tools, your team can avoid these issues.