As development teams increase the speed of their release cycles, regression testing will be an essential part of their processes. Today, many engineering teams are releasing updates weekly, daily, or even multiple times in one day, and while this increases the pace of innovation, it also increases the chance that bugs introduced in new code will cause problems for functioning software. For fast-moving teams, the purpose of regression testing is not only to ensure quality but also to provide stability by ensuring that velocity doesn’t create instability in existing features.
Why Regression Testing Matters in Rapid Development Environments
Software systems are continuously changing and developing. New features are being added, existing functionality is changed, and integrations are increased over periods of time. Every time a code change is made, there is a risk that parts of the system that were working successfully before may not work correctly anymore due to the change.
If consistent regression testing is not performed when making small modifications to applications, you run the risk of creating unexpected failures across the entire application. Those issues may not be seen until after they appear during user interactions with those components that were affected by a code change.
Rapid release cycles amplify the risk of causing regression issues with each code change. When teams release frequently, they have reduced time available for manual validation of the application. Reliable regression testing will allow you to have confidence in shipping code quickly while maintaining application stability.
Establishing a Reliable Regression Testing Strategy
While running the same test cases repeatedly is considered effective regression testing, it shouldn’t be done in an unstructured manner. An effective regression test strategy needs to be created by developing a structured plan that balances speed, coverage, and maintainability of tests.
Identify Critical Work Flows
An important step before developing your test strategy is identifying the critical workflows in the system. Not every piece of functionality has equal levels of risk; therefore, teams need to focus on identifying the critical workflows that are directly tied to users or severely affect the company’s core business functions.
Examples include:
- Authentication and Access
- Payments
- Data Storage and Retrieval
- Core Application Services
By focusing on the identification of the critical workflows, the risk of losing the stability of critical functionality due to rapid changes in systems is minimal.
Keep Your Test Suite Focused
With every change made to a system, the number of tests that are executed can grow. Over time, executing every single test case for every change becomes less effective.
A good test suite is one that has been developed to focus on the validation of high-value tests that validate important behaviours. Making sure tests that are redundant or no longer add value are deleted, and the remaining tests can still execute in a timely fashion, will assist with maintaining the amount of coverage.
Automate Your Recurrent Validation Efforts
As applications become more complex, the difficulty of doing manual regression testing increases. The act of repeating the same validation processes multiple times over many different releases can also take up an immense amount of time and energy.
By utilizing automated testing, teams can run their regression test suites in a consistent manner across all of their various builds and environments. Additionally, utilizing automated testing reduces the chance of human error and provides teams with faster feedback during the development process.
Automated testing is especially valuable when integrated into continuous integration pipelines, which allow for automated test execution to take place after every code modification.
Evaluate Your System Integrations
Failure of many systems occurs at their integration points. It is also common for APIs, databases, and third-party integrations to be regression points.
Regression testing should include evaluation of the interaction points between your integration points. A small change to one integration point may still affect the way that it communicates with another.
Testing interactions between components will enable you to identify defects before they reach your production environment.
Combining Different Testing Approaches
The strategy for keeping your system in balance can include many different methods for testing the way that the system behaves.
There are some teams that also incorporate some black-box tests that test the functionality of an application based on how the user will interact with the application. By using this technique, you can test for functional regressions that may not show up in your component-level tests.
Using different types of testing perspectives will increase the possibility of detecting subtle defects that may be introduced when other changes are made.
Integrating Regression Testing into Development Workflows
The integration of regression testing into your development process can be of great benefit to fast-paced teams. Continuous integration (CI) provides a great way to do this. By utilizing CI with your code changes, an automated regression check will always be run for any code changes prior to merging changes into a common branch.
In this manner, you will find any defects as soon as possible and stop any changes from being made that are of questionable quality before they move through the development pipeline.
When regression tests run automatically in your development pipeline, the feedback to your team will be much faster and will also provide your team with more confidence in their products.
Common Challenges in Regression Testing
Even well-planned methods will be subject to some difficulties as systems develop.
While larger test suites can make execution slower and affect the speed of a development workflow, it may also be very difficult for teams to maintain their tests as they have other issues to worry about, as and when the application changes.
Another problem with balancing speed versus coverage occurs when it is impractical to run all tests after every single code change; therefore, groups of tests are created that contain fewer tests but will run multiple times in different areas of the pipeline.
The right way to help maintain effective regression tests as your system evolves is to continue to assess and improve the quality of your regression test suite on a regular basis.
Building Long-Term Stability Through Regression Testing
Regression testing has more than just the purpose of finding defects; it also aids in the establishment of long-term reliability for a system.
Teams that implement effective regression testing best practices experience fewer unanticipated operational issues and roll out product updates quickly and confidently while responding promptly to new business needs.
Over time, as regression testing becomes part of the engineering culture, developers expect there to be continuous validation of their work; therefore, they incorporate testing as a regular part of their development cycle instead of performing it all at once after their development is completed.
Conclusion
Opportunities and Threats stem from rapid development cycles. Rapidly developing features mean that teams can produce new features, but their ability to produce new functionality has the effect of increasing the risk that changes made will have an adverse effect on already developed functionality.
Implementing a thoughtful strategy for regression testing can mitigate this risk. By focusing regression testing based on what is the most critical workflow, keeping test suites streamlined, automating the process of completing the validation/testing of software, and including the testing process in the development pipeline, allows an engineering team to drive continued stability while at the same time deliver innovation.
To sum up, for the modern-day engineering team, regression testing is not a simple checklist activity; it is an equally critical process to ensure the continued delivery of reliable, trusted software.