Regression testing definition and purpose

The verification of an application’s behavior after changes in its code is the central focus of the regression testing methodology. A crucial aspect of the regression testing definition is its applicability in diverse contexts. Whether it is a bug fix, optimization change, or an update adding a new feature to the system, the product will require regression testing as long as its code base is modified.

The purpose of this testing approach is to identify any undesirable behavior in the system before it reaches end-users.

Who should perform regression testing?

Undoubtedly, software development agencies are responsible for delivering a fully functional product to their customers. To achieve this goal, they need to implement a regression testing routine. At the same time, as mentioned earlier, organizations using third-party applications with essential functionality should also conduct regression testing.

For instance, the popular ERP and CRM suite Microsoft Dynamics 365 is continuously tested by its development team, but enterprises that have adopted it should retest it. Configuring the applications in the suite, supplying them with business data, and customizing them to tailor them to the specific needs of an organization increase the probability of unexpected system behavior. Regression testing helps identify issues before they lead to serious consequences.

Strategies for Regression Testing

There are various approaches to regression testing, and in most cases, the factor that distinguishes one type of regression testing from another is the testing scope. While the most comprehensive information about the system’s behavior can be gathered through complete regression testing, it is rarely performed due to its excessive effort and resource consumption. More often, organizations have to select specific parts of an application for testing. Here are some of the most popular ways in which it can be done:

1. Partial Regression Testing

Partial regression testing focuses on one of the subsets of test cases. As a rule, the fragments of the code that have undergone changes are the primary focus of partial regression testing.

2. Test Case Prioritization

Prioritization of test cases or selective regression testing also evaluates the scope of an application only partially. However, in this case, the criterion is often the possible impact certain software elements can inflict on the processes if they happen to be affected by the code modification. In other words, software components responsible for critical functionality are tested first.

3. Complete-Partial Regression Testing

It is also possible to combine several testing approaches. Although the name of complete-partial regression testing may appear counterintuitive, in reality, it means that testing covers the entire application; however, it focuses more on certain elements than on the rest of the system.

Automated regression testing

Conventional regression testing is performed manually by developers, but the rise of automation and the expansion of functionality and complexity of software have led to the emergence of automated regression testing. The core element of testing that can be automated is the execution of test scripts, which is performed by a special framework or other tools. Depending on the functionality of the testing product, it may also be possible to automate many other related tasks, including test scheduling, generating reports, notifying of issues, analyzing test results, and more.

Tools used for automated regression testing

Initially, many applications and frameworks used for automated regression testing required programming skills for script writing. Additionally, for numerous tools, setting up testing infrastructure and integrating with other automation tools was a prerequisite. Some of these tools, such as Selenium, continue to exist and enjoy great popularity due to their open-source distribution.

However, the emergence of no-code solutions has revolutionized automated regression testing. These solutions allow users without advanced technical skills to easily create and execute testing scripts without investing excessive effort into building infrastructure. Many no-code solutions are already optimized for assessing specific software products. For example, Executive Automats can be employed to test applications within the Microsoft Dynamics 365 ERP and CRM suite.

Popular myths about regression testing

Lack of sufficient knowledge about regression testing can lead to misconceptions in organizations which can significantly compromise the testing effort.

For instance, there might be a temptation to forgo regression testing if new features are working well. However, regression testing is necessary to ensure that these features do not adversely affect other functionalities in the application.

Another myth is that regression testing is useful only for large projects, whereas in reality, projects of all sizes can benefit from it. Furthermore, the wide variety of regression testing tools dedicated to functional testing may create the impression that regression testing is solely about functional testing. Yet, it is just one of the methodologies used for regression testing, which also includes other testing types, for example, performance testing.

Bottom Line

Regression testing helps companies ensure their software is working properly after any code modifications. While regression testing is a necessary practice for software development agencies, organizations relying on third-party products should also conduct testing to ensure the applications work in their specific environments as intended.