DevOps methodology encompasses a culture focused on improving work throughout the SDLC. Within DevOps, workflows like CI/CD support a continuous development feedback loop and allow faster reliable releases. In addition to the SDLC, the software testing life cycle is another critical component to creating and releasing high-quality software products and apps.
Software testing makes or breaks product velocity and quality. Successful feedback loops that speed up testing help DevOps teams deliver the best possible product. Regression testing is one of the most important types of software testing, verifying code changes against existing functionality to ensure new changes don’t impact old code.
When is regression testing performed in software testing?
Regression testing confirms that a new code change does not negatively impact existing features. Regression testing involves running a full or partial selection of already executed test cases to ensure the existing functionalities of an app continue to perform as needed and wanted, even after a change.
Regression testing is one of many software tests within the CI/CD pipeline. Typically regression testing is needed at crucial moments during the software development life cycle. Regression testing helps determine whether or not new code or features affect other pieces of the software application. Additionally, regression testing may be needed if a functional issue or performance defect is solved.
Pros of Regression Testing: De-Risk and Shift Left
Regression testing in software testing offers up several key benefits. A significant advantage lies in risk mitigation. Regression tests allow developers to quickly assess if a new code change works by evaluating if the changes and new features are compatible with the existing software. By mimicking how the component functions within the current software in the real world, regression tests take the guesswork out of whether introducing new code will cause harm without releasing it.
The power of regression testing is uncovering new defects before they stack up. If developers perform regression testing early and often they can identify issues before they are forced to preform more exhaustive testing down the line. Regression testing saves headaches down the road and helps mitigate the risk associated with updating or adding new features to a project.
Regression tests allow teams to shift left and adopt a more Agile testing and development life cycle. Before the advent of DevOps, software testing was typically performed after software development was considered “done.” Requirements were kept on the left side of the software development life cycle, while delivery and testing were on the right. But, by opting into this older way of doing things, testing became a significant bottleneck. Testing so late in the game often unveils a flurry of errors, bugs, and issues that could be more easily addressed earlier in the game.
Shift left with regression testing - catch code breakage earlier to speed up development workflows and release times.
Cons of Regression Testing: Manual Test Selection Bottlenecks
All of that said, regression testing is not without flaws. Regression testing can be time-consuming and complex, especially if you release complicated products. If this is the case, regression testing needs complex scenarios developed and executed to ensure high-quality releases ultimately happen.
Regression testing must continuously adapt along with your software. The more updates and new features, the more regression testing you must perform. Keeping your regression test suite up to date becomes complicated when evaluating and re-evaluating new tests. This can tax developers with expanded knowledge and time demands.
Another drawback to frequent regression testing is that it often increases the size of your test suite. As an application or program grows in size, so must your regression test suite. Unfortunately, massive test suites can block your CI/CD pipeline, frustrate developers, and bog down workflow. In the worst-case scenario, developers get so bogged down with slow testing times that they’re forced to skip over regression testing to meet demands and “speed up” testing, which causes them to miss minor and significant flaws along the way.
Five Regression Software Testing Techniques
There are five standard regression testing techniques based on the type of software modifications or defect repair. Understanding each will better arm your testing strategy to ensure you have all your bases covered.
1. Corrective regression testing
Used when no new changes have been introduced in the product’s specification. Existing test cases can be reused for ease.
2. Retest all regression testing
Involves testing every aspect of an app and reusing all test cases - even if no changes or updates have been made. Retesting all regression testing is tedious, often a waste of time, and a great way to annoy your DevOps team.
3. Selective regression testing
Used to assess the impact of new code on existing code. Selective regression testing is a subset of existing test cases used to reduce the time, cost, and effort needed for retesting and the cost involved.
4. Progressive regression testing
Helps to ensure no features from a previous version have been compromised in an updated version.
5. Complete regression testing
Best used when multiple changes have been made to the existing code. Also used when critical application changes or new apps are built.
How to Automate your Regression Test Selection
Launchable helps software testing teams identify and run the most important tests to run. With Predictive Test Selection, our ML platform selects the tests with the highest probability of failing based on your code and test metadata to speed up the dev feedback loop.
Your team can harness the power of ML to intelligently choose the best regression tests to run and remove any regression tests that are unnecessary or unhelpful.
Slash your test suite size and run time while maintaining high confidence that your regression testing will always uncover issues with intelligent test selection. Launch your new features fearlessly with smarter regression tests with Launchable.