Regression Testing: What is it?

Regression testing is a vital software testing technique that helps ensure application quality and reliability during software development. It involves re-running functional and non-functional tests on an application after modifications to ensure that existing capabilities still work as expected and that new changes have not introduced defects. Though regression testing is repetitive, it provides significant benefits that contribute to building robust software applications. It is also defined as the selective retesting of an application or system modified to verify that the changes have not adversely affected the existing functionality. It aims to catch bugs introduced due to code changes and ensure that the application’s behavior aligns with the original specifications. 

Regression testing is not about re-running every test case. Instead, it requires the intelligent selection of test cases based on risk and priority. The tests selected should cover critical functionality that is most prone to break with code changes. Though regression testing is sometimes a repetitive process, it is a structured type of testing that requires careful planning.

Regression tests should ideally be executed as frequently as code changes are made, such as after each new code commit, to ensure that any modifications do not introduce unexpected defects and to maintain the software’s reliability. However, the frequency can vary based on project requirements, with some teams performing regression testing nightly, during each sprint, or in response to significant code updates. The key is to strike a balance between thorough testing and development velocity. In an ideal world, regression testing should be performed at multiple points in the development lifecycle:

When planning and implementing regression tests, it’s important to steer clear of potential pitfalls and antipatterns such as over-reliance on manual testing, neglecting test maintenance, lacking clear test documentation, and performing overly extensive testing, which can result in inefficiencies and compromised software quality. The following list outlines typical antipatterns in regression testing that should be avoided, understanding that it may not encompass all possibilities and each organization may encounter unique challenges:

Getting the most out of regression testing is crucial for maintaining software quality and reliability within the constraints of limited testing time and resources. To achieve this, it’s essential to prioritize test cases effectively. Start by focusing on critical, high-impact test scenarios that cover the core functionality of your application. Then, pay particular attention to areas of recent code changes or enhancements, as these are more likely to introduce defects. As you expand your testing scope, consider the risk associated with different parts of your software and allocate resources accordingly. By following these guidelines, you can optimize your regression testing efforts, ensuring that you address the most critical aspects of your software while working within the constraints of your available time and resources. To optimize limited testing time and resources, organizations should:

Regression testing is undergoing a transformative shift, becoming an automated and intelligent practice seamlessly integrated within the DevOps toolchain. While its fundamental purpose remains constant – to enhance software quality through continuous testing, the ongoing progress of AI-powered testing tools and methods has expanded the role of regression testing. It now handles new use cases and simplifies manual, time-consuming tasks that are part of the regression testing process. Here is a list of examples illustrating how AI is revolutionizing regression testing: