Seven Types of Regression Testing (and When to Use Them)

Key Takeaways

• There are seven different types of regression testing, each test focusing on the same goal (identifying bugs, flaws, and issues), but with varying approaches and use cases.

• Whether you’re using one or combining several, your regression testing strategy can be supercharged with CloudBees Smart Tests, which uses AI to prioritize and run the most relevant tests, boosting speed, accuracy, and confidence across your pipeline.

Regression testing remains a critical component in maintaining code quality and minimizing bugs. With the growing volume of AI-generated code, traditional regression testing methods often become a bottleneck, slowing down release cycles and driving up costs. .

CloudBees Smart Tests leverages AI-driven test intelligence to streamline testing, helping engineering teams ship code twice as fast, with higher quality, by intelligently selecting tests, automating failure analysis, and optimizing resource utilization. By prioritizing high-risk tests and eliminating unnecessary ones, it significantly reduces costs and accelerates feedback loops.

Let’s explore the seven types of regression testing and how CloudBees Smart Tests can help optimize each of them.

1. Unit Regression Testing

   • What is unit regression testing? Unit regression testing focuses on individual units of source code, such as functions, methods, or classes, to ensure they perform as expected after changes. These tests are performed during the coding phase and offer granular insights into the behavior of isolated code components.

   • When is unit regression testing performed? Unit regression tests are performed during the coding phase of an application.

   • What are the challenges of unit regression tests? Unit regression testing is essential for catching issues early in the development lifecycle, but the traditional approach often leads to inefficiencies. Manually selecting which unit tests to run can be time-consuming and sometimes miss integration-level issues.

   • How does CloudBees Smart Tests optimize unit regression testing? Cloud Bees Smart Tests intelligently selects only the most impactful unit tests based on historical data and code changes. This targeted approach reduces testing time, optimizes cloud resources, and ensures that developers focus on the most critical tests. The platform’s AI-powered debugging further streamlines failure resolution by identifying root causes quickly.

2. Partial Regression Testing

   • What is partial regression testing? Partial regression testing focuses on ensuring that new code changes don’t break existing functionality. It’s especially important when small modifications or feature additions are made to the codebase.

   • When is partial regression testing performed? Partial regression testing is performed after new code is added to existing code, and after impact analysis.

   • What are the challenges of partial regression tests? Partial regression tests for every code can betime-intensive, especially as application complexity increases. Managing and maintaining a large set of partial regression tests also requires considerable developer effort. .

   • How does Cloud Bees Smart Tests optimize partial regression tests? With Cloud Bees Smart Tests, only the tests most likely to fail are run, ensuring faster feedback and reducing cloud costs. The platform’s AI-powered test selection prioritizes high-risk tests, allowing developers to focus only on the most relevant tests. This optimization also reduces developer toil, enabling teams to focus on new feature development rather than maintaining test suites.

3. Selective Regression Testing

   • What is selective regression testing? Selective regression testing analyzes the impact of new code on existing code, focusing on variables and functions that may have been affected by recent changes.

   • When is selective regression testing performed? Selective regression testing is performed after new code is added in.

   • What are the challenges of selective regression tests? Selective regression testing can be manual and error-prone, requiring careful selection of which tests to run. It also introduces a risk of missing critical tests if not carefully managed.

   • How does Cloud Bees Smart Tests optimize selective regression tests? Cloud Bees Smart Tests automates test selection using AI, ensuring only the relevant tests are run. This reduces the chance of human error and speeds up the feedback process. By running only the most impactful tests, the platform enables teams to test more frequently and reduce costs associated with unnecessary test executions.

4. Progressive Regression Testing

   • What is progressive regression testing? Progressive regression testing ensures that existing features are not compromised when new test cases or code changes are introduced.

   • When is progressive regression testing performed? Progressive regression testing is performed when new test cases and certain changes done in the program specifications are designed.

   • What are the challenges of progressive regression tests? Progressive testing is often resource-intensive, as it requires new test cases and environments to be created and managed. Over time, as more tests are added, the process can become increasingly time-consuming.

   • How does Cloud Bees Smart Tests optimize progressive regression tests? Cloud Bees Smart Tests helps teams focus on the most critical tests, ensuring new code doesn’t break existing features. The platform’s automated debuging and AI-driven insights reduce the time spent triaging test failures, making it easier for teams to maintain high-quality standards while accelerating their release cycles.

5. Corrective Regression Testing

   • What is corrective regression testing? Corrective testing ensures that previously resolved issues do not resurface after new code is implemented. It involves re-running tests that were previously executed to ensure that issues are not reintroduced.

   • When is corrective regression testing performed? Corrective regression testing is used when there are no changes introduced in the product’s specification.

   • What are the challenges of corrective regression tests? Corrective regression testing can become repetitive, often requiring engineers to run the same tests without providing significant new insights. Without proper automation, this becomes an inefficient process that takes valuable time away from more meaningful tasks.

   • How does Cloud Bees Smart Tests optimize corrective regression tests? With AI-powered failure triage, Cloud Bees Smart Tests automatically identifies root causes, categorizing failures as either new or previously encountered. By providing context around flaky tests, the platform helps developers focus on critical issues, reducing the manual effort and ensuring faster resolution of recurring problems.

6. Complete Regression Testing

   • What is complete regression testing? Complete regression testing involves running the entire test suite after changes to the codebase. This is typically done before a product launch to ensure that all functionality works as expected.

   • When is complete regression testing performed? Complete regression testing is performed when multiple changes are made to the existing code. This kind of testing is most often done before launch, and can highlight if a new change has an effect on the root code.

   • What are the challenges of complete regression tests? Complete regression testing is often time-consuming and resource-intensive. Running an entire test suite after every code change significantly increases testing cycle times, especially as the application grows in complexity. This approach can strain CI/CD pipelines, delay feedback loops, and increase developer toil, particularly when many of the tests may not be relevant to the recent changes.

   • How does Cloud Bees Smart Tests optimize complete regression tests? Cloud Bees Smart Tests reduces the scope of tests by intelligently prioritizing tests that are most likely to fail based on code changes. This speeds up the testing process while maintaining or improving test coverage. By integrating with existing tools and workflows, it ensures optimal resource allocation, significantly reducing cloud costs.

7. Retest-All Regression Testing

   • What is retest-all regression testing? The most comprehensive of all regression tests, retest-all regression testing re-executes every single test scenario to ensure that no bugs are missed. It is typically performed before major releases.

   • When is retest-all regression testing performed? Retest-all regression testing is performed when you want to rerun all of existing tests on the new code, to uncover the regressions.

   • What are the challenges of retest-all regression testing? Retest-all regression testing can be one of the most time-consuming and tedious approaches. Running the full suite of tests after every change can lead to long cycle times, developer frustration, and significant resource drain often without proportional value. This level of exhaustive testing can slow down delivery, strain CI/CD systems, and contribute to missed deadlines or release delays, especially in fast-paced environments.

   • How does Cloud Bees Smart Tests optimize retest-all regression testing? Cloud Bees Smart Tests eliminates the need to run the entire suite by automating test selection and focusing on the highest-priority tests. This optimizes cloud resource usage and accelerates testing without sacrificing coverage, enabling faster, more reliable releases.

As development cycles shorten and complexity increases, traditional regression testing methods can no longer keep up. Cloud Bees Smart Tests transforms regression testing from a bottleneck into a competitive advantage by leveraging AI-driven test intelligence to optimize test selection, streamline failure triage, and reduce cloud costs.

Powered by your own git commit metadata, CloudBees Smart Tests analyzes your test suites, reorders tests dynamically, and pinpoints the highest-priority ones to execute - so your DevOps team gets faster feedback, without wasting time or compute cycles.

Get visibility into regression test entropy, surface flaky tests, and avoid running your entire suite when it’s not necessary. Smart Tests streamlines your QA pipeline, improving reliability, saving time, and accelerating delivery.

Smarter testing means fewer delays and more confidence in every release.

Stop running every test, every time. Let CloudBees Smart Tests show you which ones matter. Ready to accelerate your QA cycles? Book a demo today.