Regression Testing: Answers and Strategies

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Regression Testing: Answers and Strategies

Regression testing provides the best way of ensuring your application still works after that latest code push.

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Use regression testing to ensure the latest code doesn't hurt your product.


Regression testing is vital for a business to release high-quality software products to the marketplace. With a host of technical and commercial advantages, every company should make more investments in regression testing to better control the processes, resources, and budgets of their software project. This article will give you more insights into regression testing, from the definitions and benefits, to the methods to build the best tests and the automation tools supported.

Understanding Regression Testing

What Is Regression Testing?

Regression testing is a software testing practice applied to ensure the application continues to perform as expected when we add any change, update, or modification in the source code. Whenever developers change or update the code of their software, even a seemingly insignificant alteration can lead to unexpected consequences. They may involve dependencies, defects, or malfunctions. Regression testing emerges as a way to mitigate these risks so that the previously developed and tested code remains operational after new changes.

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Regression testing is responsible for the overall stability of software performance by preventing code changes from breaking the existing functionality, enhancing product quality as well as user experience. Therefore, it is generally the final step in the multiple-step testing process before the changes are integrated into the main development branch.

When Do You Apply Regression Testing?

Typically, regression testing is applied under these following circumstances:

  • A new requirement is added to an existing feature
  • A new feature or functionality is added
  • The codebase is fixed to solve defects
  • The source code is optimized to improve performance
  • Patch fixes are added
  • Changes in configuration

Why Is Regression Testing Necessary?

  • Regression testing helps detect bugs in the source code early in the deployment cycle whenever code changes. The product team can save much time and effort in resolving build-up defects after releasing.
  • Rather than functional testing that only focuses on inspecting behaviors of the new features, regression testing goes beyond to confirm the compatibility between newly added features and the existing ones. Hence, developers or tester can find it easier to investigate the primary cause of a test failure. 
  • With a software project that requires frequent updates and continuous improvements, regression testing is vital to guarantee the stability of application performance. 
  • With the fast speed of regression testing, software teams can receive more informative feedback instantly as well as resolve problems more quickly and effectively. 
  • Regression testing helps developers and testers put effort into building new features for software applications rather than turn back to fixing bugs on the previous test case. 

How to Implement Regression Testing


A typical regression testing process goes through five basic steps:

  • Detect changes in the source code: Locate the alterations in the source code; then identify the components that were changed and their impacts on existing features.
  • Prioritize those changes and product requirements: Organize the testing process based on the priorities of code changes with product requirements; then choose the corresponding test case and testing tools.
  • Determine entry point and entry criteria: Make sure the application satisfies the preset eligibility before running the regression test.
  • Determine exit point: Identify the final point for preset eligibility or minimum conditions set in step three.
  • Schedule testing time: Finally, prepare all test components or modules and schedule the appropriate execution time.


Depending on the specific test scenario, developers and testers have three options for regression testing techniques: complete regression (re-run all tests), partial regression (test selection), or test case prioritization. 

  • Complete regression:  This technique enables you to execute regression testing on all test suites. Although it is the safest way to catch all the bugs that cause problems in function, it requires a vast amount of resources and time to implement. One typical example of complete regression is when the operating system gets significant updates or when the application has to transform into a new language or platform. 
  • Partial regression: In this method, you can pick out some relevant parts that might be affected by new code changes to implement regression testing. By limiting test areas, you can save time and resources.
  • Test case prioritization: As its name supposes, you can choose some test cases to execute first. These priorities are based on some criteria such as failure rate, business impact, and gradually used functionalities. 

Regression Testing in Agile

Agile development approach has become a trend among various organizations due to a wide range of beneficial effects it brings. Product teams can enhance product quality, minimize the release time to market,  improve the return of investment or customer support system. Nevertheless, product maturity always requires continuous updates and improvements in software function, leading to a challenge to mitigate the conflicts between newly added features and existing ones. Regression testing in Agile is responsible for aligning updated and existing functionalities, prevent unexpected defects from causing detrimental effects on your product.  

Best Automation Tools for Regression testing

Regression testing can be executed manually on small projects, but in most cases, repeating test suites continuously after any code changes is too time-consuming and hard to control. Thus, automation testing tools are crucial in a software project that undergoes a tremendous number of test cases. Additionally, the right tools can significantly identify all surfaced bugs and eliminate them early in the pipeline. 

Click here to dive deep into each automation tools. 


If teams can put enough time and effort into planning a test strategy with automated regression testing, they can take significant control over budget, process, teamwork efficiency, and, most importantly, release  a more high-quality product to the market at a faster speed. 

Further Reading

3 Ways to Optimize Regression Testing

Plan Your Regression Testing Strategy by Asking the Relevant Questions 

automation testing, automation testing tools, devops, regression testing, source code, testing implementation

Published at DZone with permission of Oliver Howard. See the original article here.

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