Regression Testing is a type of software testing process that ensures that recent program or code alterations have not adversely impacted existing functionalities. Its primary purpose is to identify whether a code change has resulted in unexpected issues, ensuring that previously rectified bugs continue to stay fixed. This testing method is highly valued as even minor modifications can lead to significant software malfunctions.

What is Regression Testing?

Regression Testing involves re-executing functional and non-functional tests to validate that a software application still operates as expected after any modifications, updates, enhancements, or optimizations are made to the code. This process helps maintain the overall stability of the software application by ensuring the functionality of the existing features is not compromised or disrupted due to the integration of new code changes.

For example, consider a social media platform that initially allowed users to log in using an email address. If a new feature is added to allow users to log in using a social media account, regression testing would be conducted to ensure that the new feature does not interfere with the existing login functionality.

The Importance of Regression Testing

Considering the complexity of modern software applications, regression testing plays a critical role in maintaining software stability and reliability. It aids in catching bugs that might have been accidentally introduced into a new build or release candidate, and ensures that previously fixed bugs continue to stay resolved.

Moreover, the rapid regression testing process allows product development teams to receive informative feedback, which can be responded to immediately. This enables faster modification of the software code, leading to the prevention of bugs in the early stages of the software development cycle, thereby saving businesses from investing in maintenance efforts in terms of both time and cost.

When is Regression Testing Performed?

Regression testing typically takes place in the following scenarios:

1. When new functionality is added: If a new feature is incorporated into an existing application, regression testing is performed to ensure the new functionality does not disrupt the existing features.
2. When there’s a change in requirements: If the project requirements change, regression testing is performed to ensure that the new requirements do not break the existing functionality.
3. When a defect is fixed: When a bug is fixed in the application, regression testing is performed to ensure that the fix did not introduce new issues.
4. When performance issues are fixed: If performance issues in the application are resolved, regression testing is carried out to ensure that the fixes have not led to new bugs.
5. When the environment changes: If there is a change in the environment (like a database change from MySQL to Oracle), regression testing is done to ensure the application continues to work as expected.

Building a Regression Test Suite

Building a robust regression test suite involves several crucial steps:

Step 1: Identify changes in the source code. This involves identifying the source code changes and recognizing the changed components and their impact on the existing features of the software.

Step 2: Prioritize identified changes and product requirements. All identified product requirements and code modifications are prioritized, aligning the test process with the necessary tools and test cases.

Step 3: Select test cases to re-run. Next, the test cases to re-run are selected based on the source code-modified module. Here, there’s no need to test the entire test suite.

Step 4: Determine the execution time of test cases. Test case variables, such as test data preparation and regression test designs, are evaluated to determine how they impact the test case execution time.

Step 5: Categorize automated and manual test cases. This step separates the test cases into automated and manual ones. Automated test cases are faster than manual cases managed by humans.

Step 6: Prioritize test cases. In this step, the test cases are ranked based on their significance (high, medium, low).

Step 7: Schedule and execute test cases. Each test case is individually conducted at an appropriate, scheduled time to verify if the product performs as expected.

Regression Testing Tools: Top Picks

Several quality regression testing tools are available in the market. Here are some of the top picks:

1. Katalon Studio: This tool is known for its AI-powered testing capabilities, which make testing faster, smarter, and more efficient. Katalon Studio supports multiple programming languages and platforms, and it provides seamless integration with popular tools such as JIRA, Slack, and GitHub.
2. Selenium: Selenium is a popular open-source framework for automating tests on web browsers and supports cross-platform regression testing. It allows the creation of test scripts in various programming languages.
3. Apache JMeter: Apache JMeter is an open-source automated regression testing tool mainly used for performance testing, load testing, and functional testing of web applications.
4. IBM Rational Functional Tester: This tool from IBM offers automated testing for functional, regression, GUI, and data-driven testing. It features a natural language script editor and rendered screenshots for easy test visualization.
5. Testsigma: Testsigma is a comprehensive end-to-end AI-augmented automation testing platform that can streamline your regression testing process. It supports various platforms, browsers, and devices, and allows you to execute multiple tests in parallel.

Conclusion

Regression testing is an integral part of the software development and maintenance process. It ensures that the software application remains stable and functional, even after changes have been made to the code. By employing effective regression testing techniques and tools, software development teams can identify and correct problems early in the development cycle, resulting in higher quality software and improved customer satisfaction.