What is regression in software development?

What is regression in software development

Software development goes through various stages in its life cycle to get to a complete feature set or product. These stages include planning, requirements analysis, design, implementation (development), testing, deployment, and maintenance.

During the Software Development Life Cycle (SDLC), there may be bugs or regressions present that can hinder the quality of the built product. 

Bugs are faults, flaws, or errors in programming that cause a product to behave in unexpected ways. 

Bugs are a common occurrence in software development. They can exist in any phase of the software development process and are found through testing. While no application will be 100% bug-free, most bugs can be caught and fixed for a smooth functioning product through proper development and testing procedures. 

So what is a regression?

In software development, regression refers to the reoccurrence of a bug or defect that was previously fixed or a previously working feature that is no longer functioning as expected after making changes or introducing a new code release. It occurs when new code changes or updates unintentionally introduce errors or disrupt the existing functionality of the software. Such as, system upgrades, feature enhancements, and previous bug fixes through patching. The most common cause of regression is usually bug fixes.

How can you deal with regressions?

Preventing regressions requires regression testing. This step in the quality assurance process involves re-running tests on completed work. Whenever new code changes, it is essential to perform this step to ensure that recent changes do not adversely affect the software’s existing functionalities. 

For example, every time a bug is found and fixed, a regression test is warranted, whether manually or using automated testing tools. 

Regression testing uses test cases from the test suite. Test cases are a set of executable actions used to verify the functionality or feature of an application. These tests can be functional tests or unit tests. Functional Tests verify an application against functional (user input on the application) requirements or specifications. Unit Testing deals with testing an individual unit or component of code to make sure that it performs as expected. Unit testing is specifically to test the interaction between pieces of the code rather than the user functionality of the software.

Various techniques when performing regression testing 

Retest All involves re-running all test cases in the test suite to check for errors or problems. This method can be expensive and time-consuming. 

Regression test selection involves selecting test cases from the test suite to re-run and check if any code changes negatively affect the application. 

Test case prioritization involves selecting test cases based on priority, such as more commonly used features. It focuses on executing the more critical test cases first.

Many issues can cause regressions in an application, such as changes to software due to bug fixes, inadequate version control, changes in system configuration, and more. Regression testing will help identify these issues in the software based on changes to the system. Hence, developing a good regression strategy will save you time and money.

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