In software development, even minor changes can trigger a domino effect of unintended consequences. Whether it’s introducing a new feature, bug fix, or update, there is always the risk of disrupting the existing functionality by implementing new logic that conflicts with the existing code. Regression testing is a crucial process that ensures that everything runs smoothly and no sneaky bugs have slipped in.
To gain insights into this topic, we talked with Andrii, our Test Automation Engineer with years of expertise in quality assurance. In this blog post, we provide a comprehensive overview of regression testing, covering its importance, challenges, tools, tips, and best practices you need to know.
What is regression testing?
Regression testing is a type of software testing that ensures that recent code changes have not negatively affected the existing functionality. The name “regression” comes from the process of re-running previously passed test cases against new code to verify that the software continues to work correctly despite the changes. Generally, it involves re-executing a series of tests whenever a new change is introduced.
Overall, this process is a crucial part of the software development lifecycle because it helps maintain the integrity of the software after updates, bug fixes, or enhancements. Without regression testing, it becomes more difficult to find and fix issues, which as a result harms user experience.
How do you identify which test cases should be included in regression testing?
One of the common ways to approach regression testing is to “retest everything”, which is obviously time- and resource-intensive. Rather than re-executing all tests on the system, it is better to identify test cases that cover the areas of the software most likely affected by the changes.
To select the cases for regression testing, we typically use the following strategies:
- Prioritization of test cases. Focusing on tests related to the recent changes, critical functionalities, and areas with a history of defects.
- Impact analysis. Analyzing the scope of the changes to understand which functionalities might be affected and select tests accordingly.
- Requirements traceability. Using a traceability matrix to ensure all requirements are still met by existing tests, adjusting as necessary for recent changes.
What are the key challenges faced in regression testing, and how do you overcome them?
As with any other type of test, regression testing is not without its challenges. In my experience, some of the biggest challenges include:
- Time and resource constraints. As the software codebase grows in complexity, so does the test suite. Executing all tests can become time-consuming and may even lead to bottlenecks in the development process
- Test maintenance. Keeping the test suite up-to-date with changing requirements and codebase can be challenging as well. New features and updates often require the creation of new tests, while legacy tests have to be either constantly updated or removed.
- Selecting relevant tests. Including every single test in the regression cycle can be tempting, but it’s highly impractical. Finding the optimal balance and identifying which tests to run to maximize coverage without wasting resources is also an ongoing battle.
However, there are some strategies that help us overcome these challenges:
- Automate testing. Implementing automated testing frameworks significantly speeds up the process and frees up resources. It’s particularly effective for large and repetitive test suites.
- Test prioritization. By focusing on the most critical and high-risk areas, we ensure that the most important and frequently used functionality works smoothly. This approach optimizes testing efforts and ensures maximum test coverage.
- Continuous Integration. Integrating regression testing into the CI/CD pipeline ensures that testing is part of the regular development process. This practice enables early detection of issues introduced by new code and allows us to address them before they become bigger problems.
Which automation tools and frameworks do you typically use for regression testing?
Well, the choice of the toolbox depends on the specifics of the project. There are several popular frameworks for this task, including Selenium, Jenkins (for integration with CI/CD pipelines), TestNG, and Cucumber. Each of these offers robust frameworks for automating browser-based applications, integrating with development tools, and support for behavior-driven development (BDD).
Are there any scenarios where manual regression testing may be preferred over automated regression testing?
Automated tests definitely can’t replicate every user interaction. So, there are certain scenarios where manual regression testing is the best idea. Let’s delve deeper into these scenarios:
- Exploratory Testing. The goal of exploratory testing is to uncover unknown issues rather than verify known functionalities. This type of testing heavily relies on the tester’s intuition, creativity, and domain knowledge to explore the software and find potential issues.
- UI and Usability Testing. Automated regression tests may not be able to detect visual or usability issues as effectively as manual testing. Manual testing enables testers to assess user interface elements, layout, responsiveness, and overall user experience through hands-on interaction.
- Complex Test Cases. Some tests might be too complex to automate efficiently. Complex business logic, edge cases, or scenarios involving multiple systems or dependencies may require human judgment, critical thinking, and domain knowledge.
Can you share any tips or best practices for successful regression testing in DevOps environments?
When it comes to regression testing in DevOps environments, there are a few golden rules to live by:
- Integrate early and often. By incorporating regression testing into the early stages of the development cycle and running tests frequently, you make sure that all issues are caught and addressed early before they snowball into big problems.
- Automate where possible. Nobody likes doing the same tests over and over again as new features come out. Automate repetitive and high-volume tests to save manual efforts for areas requiring human judgment. Maintain test suites. Just like any other technology, test suites need regular maintenance to run smoothly. Make sure to regularly review and update test cases to keep them relevant and efficient.
- Leverage feedback loops. Testing is not only about finding bugs, it is also about improving your product. Take your time to analyze the feedback from testing to refine both the testing process and the product itself.
- Collaborate across teams. In the DevOps environment, collaboration is key to success. Ensure clear communication and collaboration between development, testing, and operations teams to align goals and share insights. When everyone’s on the same page, it’s easier to tackle any challenge.
Bottom line
As your application evolves, regression testing becomes an even more vital part of your development process, ensuring that your application continues to function smoothly. So, if you want to deliver high-quality user experiences and fault-free software, including regression testing in your testing strategy is one of the ways to achieve it.