Regression Testing in Agile: Basic Concepts, Considerations & Challenges

Regression Testing in Agile: Understanding the Fundamentals

In agile development, software testing is a critical component that evolves with each sprint. To ensure that new changes do not disrupt the existing application functionality, testers perform regression testing.

With the frequent build cycles and continuous changes that are added to the application in agile development, regression testing is vital. Therefore, the testing team needs to develop and continuously improve the regression suite from the onset of product development alongside the development sprints to guarantee successful regression testing in agile.

Regression Testing Methods

There are three ways to undertake regression testing: re-test everything, selective re-testing, and prioritized re-testing.

• Re-test everything involves rerunning all existing tests on the new codebase. If the tests were well designed, this will isolate regressions. However, this method is resource-intensive and may not be feasible for a large codebase.
• Selective re-testing involves identifying a subset of your existing tests that can address all or almost all of the “moving parts” of your codebase. It is then sufficient to re-run that selective set to discover regressions across the codebase.
• Prioritized re-testing is used on large codebases. The priority tests address code paths, user actions, and areas of functionality expected to contain bugs. Once these tests have run, you can complete the remaining tests.

Automated Regression Testing: Important Considerations

Regression testing requires constant repetition. Consider the following factors when you want to start:

• Manual tests are a starting point.

If you try to write automated regression tests against a feature in development, you could waste time writing against a volatile feature. Thus, you should only conduct regression testing once you have run and passed a test manually at least once. Only then can you compare the results of the manual run and the automated test.

• Don't aim for 100% coverage.

It's not necessary to achieve 100% coverage when it comes to regression testing. Instead, focus on covering 70-90% of manual tests with effective and repeatable scripts. The remaining 10-30% of test cases may only uncover bugs sporadically or generate false negatives or positives, making them unsuitable for regression testing. Attempting to achieve 100% regression test coverage can actually be counterproductive, as it can unnecessarily drain testing resources.

Regression Automation Challenges

Your team should know the obstacles that can set back automation efforts:

• Maintenance – Automation regression test suites are not valid indefinitely. A test suite should be quickly modified to accommodate changes in the system or application under test. However, maintaining an automated regression suite can be a challenging task, especially when the software under test undergoes frequent changes. As the system evolves, new features are added, existing functionality is changed or removed, and new bugs are identified and fixed. In such scenarios, the automated test scripts must be updated to reflect the latest changes.
• Script Robustness – The test scripts should be designed to handle all possible exceptions that may arise during test execution. However, scripting errors, unexpected events, and unanticipated test scenarios can still occur, leading to test script failures. These failures can be time-consuming and expensive to debug, especially if the root cause of the failure is not immediately apparent. To prevent such issues, test scripts must be designed with robust exception handling and error recovery mechanisms.
• Test Data Management – It requires a considerable amount of test data to ensure that the system under test is thoroughly tested. Managing this test data can be a challenge, especially when dealing with large and complex systems. Inaccurate or incomplete test data can lead to false positives or negatives, compromising the effectiveness of the automated test suite.
• Test Environment Management – Automated regression testing requires a stable and reliable test environment. However, maintaining such an environment can be a challenging task, as the test environment may include a wide range of hardware, software, and network components. Additionally, changes in the test environment can affect test results, leading to false positives or negatives. To mitigate these issues, test environments must be carefully managed, and any changes to the environment must be documented and tracked.
• Integration with CI/CD – Continuous Integration/Continuous Delivery (CI/CD) pipelines have become an integral part of the software development process, and regression automation testing is no exception. However, integrating automated regression testing with CI/CD pipelines can be a challenge, especially when dealing with large and complex systems. Try WeTest's Automation tools, one of the top products on the market, to bring you the most convenient and fast testing experience. To achieve seamless integration, WeTest is designed to run in a headless mode, generate meaningful test reports, and integrate with popular CI/CD tools.