Regression Testing in Software Testing: Types and Examples

Regression testing plays a crucial role in software development process simply because it ensures that any changes that have been introduced in the code or updates / modifications carried out during the development process does not obstruct the existing functionalities of the software application. Hence, it is carried out as and when needed during the software development process. In this article, you will get to know about the types of regression testing along with a relevant example.

What is regression testing?

It is a testing method that ensures a software product or application works seamlessly, despite updates, revisions, enhancements, optimizations or code alterations being carried out in the software application.

Types of regression testing:

1. Selective regression testing: The test coverage is limited to just a pre-made group of selected test cases. So, instead of the entire software suite being retested, a few selected components need only be tested by developers.

2. Retest-all regression testing: Each test case is re-deployed in the testing suite to make sure that the source code modifications does not produce any new bugs. A considerable amount of time and effort is required to carry out this regression test method.

3. Corrective regression testing: When the source code of the software application has not gone through any changes or modifications, then this regression test type is considered to be an ideal one. The existing system functions are checked to ascertain whether they are working appropriately or not. The current functionalities and their test cases are tested accordingly. New test cases or codes need not be written here.

4. Partial regression testing: The impact of new functionalities being incorporated into the system are measured by developers. For example, when a new source code line is being incorporated, then how it may impact the software product is examined by the team. Simultaneous testing of both old and new functionalities takes place.

5. Progressive regression testing: The testing requirements are upgraded and new test cases are developed through this testing type. When new functionality needs to be introduced and incorporated into the system then this testing method is preferred by developers.

6. Complete regression testing: The whole system is tested by the developers in a single go. The focus is on examining whether one or more modules that are incorporated will impact and alter the user experience or not. When the product is just about to be released, complete regression testing is carried out.

Regression testing example:

For instance, there is a project wherein an editing app needs to be developed. Main client requirements need to be adhered to and basic features need to be used to build the initial. Regression testing is performed by using 400 test cases and making sure that the editing app can function properly.

Once all the regression tests are carried out on the editing application, the copy needs to be mailed to get client’s feedback. But, suppose, the client is interested to add a few more features in the app then the requisite features are developed and then incorporated into the app. A regression test should be performed again as new codes have been incorporated. To check the app’s functionality, around 100 new test cases have been written and devised.

There is no doubt that these new cases should be considered, but, regression testing should also be performed on the old 400 test cases. This is done to make sure the existing functionalities are not impacted by the new test cases.

Conclusion: Regression testing is having its strategic importance in software development process. It does the work of refining the code, each time changes, updates or modifications are done to it. The testing team must have a clear idea to utilize the platform of regression testing productively.

About the author: I am a technical content writer focused on writing technology specific articles. Software testing is one of the areas in which I’m really interested. In this article. I have tried to provide some meaningful information about the types of regression testing.