The Do’s and Don’ts of Regression Testing The modern-day SDLC methodologies such as agile, CI/CD, and DevOps are flexible enough to incorporate change requests in each sprint, which increases the probability of introducing errors in existing functionality. This makes validating existing functionality, detecting newly introduced bugs, and resolving them mandatory in each build release. Whether manual or automated, such software testing is widespread and referred to as regression testing. According to Gartner’s peer community survey, 27% of the participant companies allocate 26-50% of their software testing budget to regression testing, while 61% spend up to 25% of the total testing budget on it. These stats highlight how regression testing has become integral to iterative development methods. Failing to test each sprint can result in bugs, a degraded user experience, and a loss of customer trust. In this article, we’ll cover challenges and fundamental rules for executing regression tests. Common Challenges in Regression Testing To succeed in regression testing, you must be aware of its known challenges so you can overcome these appropriately and proactively. a. Time and Resource Intensive Executing comprehensive tests can be time-consuming and risk missing critical bugs because of the following factors: It is necessary to execute all the test cases for the updated module to uncover any errors. Depending on the code’s nature, interdependent features are subject to regression cycles, expanding the testing scope. In some instances, unexpected and untested challenges may arise, and the best course of action is to seek assistance from the technical support team, leading to longer testing times. Having the same testers perform testing often can become boring and cause them to lose focus. As a result, they could miss critical issues. All of these factors together slow down development, requiring more resources to speed it up. These resources may involve more testers or automation tools. However, using them repeatedly can increase costs and extend the timeline due to collaboration or troubleshooting issues. b. Complexity Management When changes are made to a project, regression testing ensures that both the previous test cases and the impact of new or altered functionality on existing features are examined. This increases the number of test cases and their complexity, making it essential to prioritize and manage them to balance cost and ensure test coverage. c. Maintenance Maintaining a regression suite is challenging as it requires meticulous effort to update test cases regularly to reflect application changes. Otherwise, they cease to be relevant to the scope. For example, a form’s “Submit” button is enabled only when all the required fields are filled. Now, when two new mandatory fields are added to the form in the latest build release, you will have to test the button’s behavior for these fields as well. Whether a regression suite is manual or automated, its ongoing maintenance can be labor-intensive and prone to errors. These intricacies are inevitable, but specific measures, explained below, can always be taken to tackle them. In the next section, we’ll discuss what successful companies do and avoid regarding regression testing. Do’s and Don’ts of Regression Testing A comprehensive strategy is key to successful regression testing. Understanding the dos and don’ts of regression tests can make the task more manageable and efficient. Do: Start Early Implement testing strategies from the beginning of the project to allow for timely bug detection. This can be achieved in the following ways: Continuous Integration (CI): Implement a CI pipeline with automated regression tests. This enables you to get immediate feedback when the test cases are run automatically with each code commit. Test-Driven Development (TDD): This practice refers to the process of writing tests before the actual code. It ensures that each new piece of code is instantly validated. Don’t: Undervalue Continuous Integration Agile and CI/CD pipelines are the most common incremental software development approaches. They allow for requirements and early release flexibility. However, these methodologies cannot succeed without the integration of regression testing. Regression tests enable continuous feedback and improvement, which are necessary for the success of each sprint. That’s why you should ensure continuous integration of regression testing in your development process. Do: Automate Where and When Possible It is a good idea to automate test cases that are repetitive and do not change frequently. This saves time and resources while maintaining consistency in test execution. Once regression test cases are automated, you can run as many cycles as needed without worrying about conflicting schedules and availability, which are the main reasons for delays in manual testing. Automating these tests also reduces the possibility of human errors that can occur during manual testing. Don’t: Rely Too Much on Automation While automation is essential, some tests need manual intervention for accuracy. For example, issues related to UI/UX updates require human judgment. Automation scripts cannot determine if the text area expansion is crossing the page borders or if the new font is too small for normal human vision. Additionally, in some cases, it’s better to stick with manual testing for complex or frequently changing apps, rather than investing time and money in automation. As a result, relying completely on automation is not advisable as not everything can be automated. Do: Prioritize Test Cases Given that regression testing can be time-consuming, it’s crucial to prioritize test cases for essential business features and areas of the application most susceptible to change. For instance, if a banking application introduces a new security layer, the primary test cases to focus on would include withdrawing, transferring, and crediting payments. In this scenario, testing the process of adding or deleting a new beneficiary would not be a priority for this update. Don’t: Ignore Non-Critical Areas A common mistake among QA teams is to not thoroughly test features that are considered simple and non-critical. They often prioritize testing critical functionalities and overlook the fact that minor features can also introduce significant bugs. For example, an SQL query that retrieves a user’s data to display on the front end may be overlooked because it doesn’t modify the data. However, it’s incredibly important to test this simple query for various scenarios, such as testing how the display behaves when data is deleted, invalid, or requires authentication. A faulty or incorrect display can harm the company’s reputation. Do: Maintain a Comprehensive Test Suite In addition to automating and prioritizing test cases, maintaining regression test suites is equally essential. It involves updating the test cases promptly and regularly to align with code changes. If test cases are not maintained, it can be difficult to determine how the application behaves with changes or ensure comprehensive coverage. Proper maintenance prevents wasting time on obsolete test cases from previous sprints. Don’t: Neglect Test Maintenance QA teams often delay updates due to busy schedules and heavy workloads, resulting in outdated and redundant tests. Valuable knowledge held by experienced team members isn’t always transferred when the QA team changes or when new members join. This makes it hard to distinguish between accurate and inaccurate test cases. Neglecting the maintenance of regression testing can lead to obsolete tests. As a result, QA teams should regularly review test suites to remove outdated test cases, preventing delayed release cycles and unnecessary spending. This practice also ensures that code changes do not generate false positives and negatives. Do: Use Parallel Testing To speed up testing, bug fixing, and development, optimize resource use and run tests in parallel across multiple environments during iterative regression cycles. Don’t: Skip Regression Testing After Minor Changes Even small changes can have unforeseen impacts on the system. Therefore, regardless of your extensive experience, expertise, and great influence on the team, skipping regression tests should not be an option in your testing plan or strategy. Do: Document Test Plans Without documented test plans, testers can easily deviate from the intended course during regression testing, which is already a comprehensive and exhausting task. Therefore, it is crucial to document test plans and results to ensure consistency and quality in testing practices. Don’t: Forget to Assess Test Coverage The success of regression testing doesn’t depend solely on updated test cases or increased automation. Other crucial factors, such as test coverage, also play a significant role. Ask yourself whether your regression suite covers the application’s major functionality. If only a few bugs are uncovered while many remain undetected, then the testing purpose isn’t served, as these unidentified errors will impact the application’s flow. Therefore, it is important to ensure that your regression tests cover all relevant parts of the application. Ignoring test coverage can have severe ramifications, as partial testing cannot guarantee that the rest of the features are functioning correctly. Final Thoughts Regression testing is not simply about validating code changes to approve development efforts; it is about strategically finding bugs, errors, exceptions, and defects that may occur due to software updates. To achieve efficient results, it’s essential to learn and overcome the challenges associated with regression testing by following the guidelines mentioned above and avoiding common mistakes. If you need help streamlining your testing processes and improving test results, schedule a call with an expert on our team to learn how Testlio can help you drive unmatched quality.