Regression Testing: Best Practices For Ensuring Software Quality and Preventing Defects
Do you want your software to succeed in the market? One of the significant parameters contributing to the success of your software is how smoothly and accurately it functions.
For software to work seamlessly, several testing processes need to be conducted, such as functional testing, accessibility testing, integration testing, and more. In software testing, the QA team identifies and fixes bugs in the product code. However, it is common for other bugs to appear after a bug has been fixed.
Regression testing is a vital step in the software testing process. It is the process of retesting modified software to ensure that changes made to the code have not caused any unintended side effects or introduced any new defects into the system. This type of testing is essential to ensure the software functions as expected and meets the desired quality standards.
In this blog, we will discuss some best practices for regression testing that can help you ensure the quality of your software.
What is Regression Testing?
Developers need to change the program code whenever the scope of software changes or needs enhancements/modifications. Even the slightest change can cause plenty of bugs and errors in the software. Testers must mitigate these errors for software to run smoothly and work as intended.
Regression testing is a type of software testing performed to ensure that changes or enhancements to an existing software application do not adversely affect the existing functionality. It is a crucial step in software development as it helps identify any defects or errors introduced during the code modification.
Types of Regression Testing
Several types of regression testing can be performed, depending on the changes made to the software application. This section will discuss the various types of regression testing and their significance.
- Unit Regression Testing
Unit regression testing is performed on individual software units or modules. It is conducted in isolation to ensure that any changes made to the code of a particular module do not affect the functionality of other units. It helps detect any defects or errors that may have been introduced while modifying a single unit.
- Selective Regression Testing
Selective regression testing determines how the code behaves when minor product improvements or enhancements occur without impacting the existing code of a product. This type of regression testing requires a detailed analysis of minor changes introduced, like variables and functions, to ensure the critical functionality of the software application remains unaffected.
- Partial Regression Testing
This type of regression testing identifies the issues when new code is pushed to an already-existing code. It ensures that the existing functionality of the software application is not influenced by adding the new code.
Partial regression testing is usually performed when only a few changes have been made to the software application and do not impact the overall functionality.
- Complete Regression Testing
Complete regression testing is ideal if multiple updates run on the existing code that can cause a massive impact. This type of regression testing identifies unforeseen bugs and mitigates them to ensure an application still functions as expected after any code changes, updates, or improvements. In addition, testers can repair any modifications made during the testing process.
- Corrective Regression Testing
It is one of the simplistic and low-effort regression testing approaches. This type of testing is performed when no changes to the product specification occur. Hence, It is also possible to reuse the current test cases to implement the expected test.
- Progressive Regression Testing
Ensuring the software application's quality and detecting defects or errors during development is essential. Progressive regression testing is performed continuously throughout the software development lifecycle. This type of regression testing ensures that any minor changes made to the software application are thoroughly tested and do not affect the existing functionality.
- Retest-all Regression Testing
It is the process of re-executing all the test cases to ensure that no bugs or errors remain due to code changes in an application. Since it requires verification of the system specifications from the origin, it needs immense support from the QA front.
Why and When to Perform Regression Testing?
Regression testing ensures that any changes made to the software do not adversely affect the existing functionality. This section will include the reasons and times you should perform regression testing.
- Adding New Features to the Software
Whenever there is a requirement to add new functionality to the software, you should perform regression testing to ensure they do not adversely impact the existing functionality.
- Change in the Code
When there is any change requirement, regression testing should be performed. For instance, removing the “Remember Password” button will require some changes in the code that introduce any new errors.
- Software Environment Changes
Changes in the software environment, such as the operating system, browser, or hardware, can cause errors. Therefore, regression testing needs to be performed to ensure that the software works correctly in the new environment.
- To Fix a Software Defect
Sometimes, fixing a bug can cause new bugs. Therefore, fixing any defect in the software should end with regression testing to test other functionality.
- At Regular Scheduled Intervals
Regression testing should also be performed at scheduled intervals, even if there are no code changes, environment changes, or bug fixes. This helps ensure the software continues functioning correctly and meets the desired quality standards.
7 Best Practices for Regression Testing to Ensure High-Grade Software Quality
- Plan Your Regression Testing Strategy
The best practice you must ensure is proper regression testing strategy planning. Understand the project requirements, identify the user flow, and test cases that need to be retested. You need to prioritize these test cases based on their importance in the software.
You can use various regression testing to identify the critical test cases that need to be retested, such as risk-based testing, impact analysis, and code coverage analysis.
- Automate Regression Testing
Since regression testing can be time-consuming and repetitive, it is better to automate it. With automation regression testing, you speed less time on repetitive tasks, freeing up resources and ultimately saving time and effort. At the same time, less human intervention in automated tasks means enhanced accuracy and consistency of the testing process.
You can automate regression testing using various tools and frameworks like Selenium, TestComplete, and Appium. Several platforms are available in the market that can help in automating regression testing; one such example is LambdaTest.
LambdaTest is a cloud-based digital experience testing platform that enables developers and testers to perform real-time and automation testing over more than 3000+ different environments and real devices. LambdaTest provides an online device farm to perform regression tests on your websites or web applications. With LambdaTest, you can also scale up your automation regression needs using Selenium Grid to execute multiple tests in parallel, which eventually helps reduce the execution time.
Here are some benefits offered by the LambdaTest platform for regression testing:
- Allows you to do image-by-image or pixel-by-pixel comparison analysis with Visual UI regression testing.
- Allows developers and testers to view functionality across different devices, browsers, and OS.
- It enables you to test your automation regression tests across 3000+ browsers and their assorted versions.
- Regularly Update Your Regression Pack
The regression pack consists of test cases performed with each new release/software update. Maintaining your regression pack with regular updates is essential to ensure they remain relevant and effective.
Monitor your regression test suites regularly for new updates so that they cover all critical test cases and scenarios. Since manually reviewing it can be time-consuming, you can use tools like TestRail and HP ALM.
- Re-Run Successful Test Cases
Re-running the test cases is a fundamental part of regression testing sorts. It ensures the change in the overall framework of the software does not affect the working functions.
When the scope/requirement of the software is changed or increased, previously reported bugs may include in your regression test cases. Hence, re-running the test cases becomes essential, which means repeating the test you have performed before.
- Conduct Regression Testing in Iterations
Regression testing in the Agile software development model conducts testing in iterations to help you identify defects early in the development cycle. Hence, with every new product increment, QA testers can focus on new functionality while maintaining stability.
Instead, you can catch defects early and fix them before they become significant issues. Moreover, the QA team can conduct regression testing in smaller iterations to ensure that tested software continues to perform after every modification. Hence, you can conduct testing before the end of the development cycle.
- Integrate Regression Testing into Your CI/CD Pipeline
Continuous integration and continuous delivery introduced automation in stages of software development. Regression testing in CI/CD pipeline can help reduce the overall test execution time and catch defects early in development.
There are several CI/CD tools, like Jenkins, Travis CI, and CircleCI, that you can use to automate your regression testing. This process is often known as Continuous testing. Integrating regression testing into your CI/CD pipeline also ensures regression testing is conducted consistently across all development phases.
Overall, it also helps to free up resources and reduce testers' dependency while enhancing the software quality.
- Use Test Environment Management
Setting up a test environment ensures a streamlined software delivery process with effective use of resources and testing tools in a controlled lifecycle. You can establish a simple, transparent testing environment to eliminate manual tasks and optimize infrastructure costs.
Depending on the project requirements, you may need a single test environment or multiple environments, which is critical for effective regression testing. Your test environment is set up to propose the actions and toolsets needed to manage projects and consistent testing across all phases.
Tools like Apwide Golive, Omnium Lite, and ServiceNow can help you create and manage test environments.
Regression testing is an essential step in the software testing process that you should perform whenever there are any changes to the code, environment, or bug fixes. By following these best practices, you can ensure that your regression testing is effective, efficient, and consistent.
With regression testing, you can ensure that your software is functioning correctly, meeting the desired quality standards, and not introducing any new defects. These practices can help you identify defects early in the development lifecycle, saving resources and time. Also, they improve the quality of your software and ensure that it meets the desired quality standards.