Any time a feature is added or improved, an application’s code is in danger. There’s no escaping it, unfortunately: Any time a developer touches an existing piece of code, s/he introduces the possibility of breakage and new defects. This is especially true, and most common, in the areas where new code meets old.
But innovation requires new code. Lots of it. So, what’s the answer to this clear, ever-present danger?
Regression testing. Its purpose is to validate the existing feature and quickly catch the defects accidentally introduced by the new code so that they don’t fester and cause bigger problems down the road.
For any product company regularly adding new features or just stringently improving their existing ones, regression testing is an important part of any QA services regiment.
How is regression testing performed?
Regression testing is done both manually and with a range of test automation tools. Automation can help you save a lot of time and increase the accuracy of your tests, so long as you choose the right test automation tool.
For regression testing to be effective, your QA team should outline the regression strategy, complete with entry and exit criteria. The team should also consider performance testing in the regression test plan - this will help validate that system performance is not impacted by changes made to other features.
For best results, regression testing should be built right into your test plan. If you’re using a hybrid, Agile-focused QA services vendor, your team will add regression testing into your effort estimate. If you’re on a 1-2 week sprint cycle, regression testing should be performed after completion of feature testing. For monthly releases, regression testing is performed weekly and, in some cases, daily.
How to select test cases for regression testing
Choosing the right test cases is the most important part of regression testing, as it ensures that you’re identifying and fixing the real problem areas. Look for test cases that:
- Have had a high frequency of defects in past releases
- Cover features that are accessible to the end user
- Cover core features of the module or application
- Cover important areas of integration in the application
- Have been drafted in response to production or customer issues
When to perform regression testing
Anytime a code change is done! This can be a performance improvement, a defect fix, a new feature - anything that involves a revision of the product’s code. Ideally, your QA team runs a regression test after the successful deployment and pass of a smoke test.
Anytime an application's code is changed, the code is in danger. Regression testing is a simple way to ensure the code functions properly as you continue to innovate. (Click to tweet)
Automating your regression tests can help make scheduling much easier. You can sync up the tests with build deployment so that as soon as a new build is deployed, the tests run on their own. This helps to catch any bugs far in advance of the release date.
Tips for creating and maintaining your regression suite
- Pick a proper identifier for your regression test cases. Designate a label (like priority level, P0) so that your QA can easily differentiate between regression test cases and feature test cases.
- Select the optimal test cases for the suite. Your tests should cover maximum functionality in minimal numbers - the fewer and more robust they are, the better.
- Groom your suite over time. The suite should only contain test cases from recent releases, and should not contain cases that are no longer active.
- Maintain your automated tests. Your automation engineers should continuously update the scripts to reflect the latest changes, if any. This will create a high stability ratio and save time for the functional QA team.
To wrap up, regression testing is a quick, simple way to ensure that your code is functioning properly as you continue to innovate and build what matters most to your customers. If you've never launched a regression suite on your own, a qualified QA services partner can help!