Let’s imagine that someone is browsing through a food delivery app. They have placed the order and made the payment. And now, the amount has been deducted from their bank. But the food delivery app doesn’t show any order confirmation. It would be frustrating for them, right?

Loopholes in the testing process create such situations. And that makes testing one of the most crucial steps in the software development cycle. To avoid these situations you need to test your application/website every time there’s a new change, feature, or update before releasing it to the customers. This is called Regression Testing.

In regression testing, you test for a known bug by re-running the test case every time a new change is made to the code base. But is regression testing just re-running previous test cases?

NO! Regression testing is conducted to ensure that recent changes or updates do not adversely affect the existing functionalities and work without breaking the system flow now or in the future. To make it simple, there are several regression testing techniques.

Regression Testing Techniques

1.    Complete Regression Testing

It is the most detailed form of regression testing which means testing everything, or all the test scripts associated with the application. It involves thoroughly examining the entire codebase to identify all functionalities that could be affected by changes and writing detailed tests for each of them.

Executing a complete regression even for a simple application is time-consuming but highly beneficial if applied from the early stages. However, it is not feasible for a complex application due to the limitations of time and the ability to replicate all active connections and integration points to stimulate the production or live server environment.

2.    Unit Regression Testing

This technique is a combination of regression and unit testing where the code is tested from a high-level perspective. It involves isolating and testing individual units or components of code to ensure their functionality after the changes/updates are made.

When any changes are made, the tester has a checklist of times to test and it is usually performed alongside other testing techniques to ensure the overall functionality of the application.

3.    Partial Regression Testing

It is a more focused and targeted approach to regression testing where the focus is on specific, critical units or components of an application rather than testing the entire system. The project is segregated into small logical units that form the application.

Testers select and prioritize the units that are most crucial to the overall functionality and stability of the application and design specific test cases for them. The rest of the modules or components can undergo unit testing.

You select the techniques depending on the size of your project and the nature of the changes being made. Also, you need a regression testing strategy to make the regression testing process more effective.

Key Steps to Build An Effective Regression Testing Strategy

In this strategy, you write a detailed outline, objectives, scope of the testing process, list of all the features that will be tested, and the outcomes that are expected. It usually depends on several factors. These include how frequently developers make changes to the application/ website, the magnitude of these changes, and which parts of the existing system could potentially be impacted.

1.    Automate Regression Tests

The whole purpose of regression testing is to ensure that the existing functionalities work just fine without any errors. But manual testing defies the aim as it’s prone to errors, time-consuming, and repetitive.

In manual testing, things like pressing a wrong key or getting a step out of the sequence are easily possible, plus a person performing the same tests repeatedly can be very mundane. Therefore, automation is non-negotiable.

Keep these points in mind while automating the test:

1. Organize regression tests into categories based on the application’s behavior. This helps in quickly identifying the area of the application when a test fails and provides valuable information to the development team.

2. Even if a test case has previously passed, it is important to regularly re-run it. This ensures that the application continues to function correctly in an agile development environment.

3. Dedicate time to thoroughly analyze the test reports, even if regression tests are performed daily. This helps in identifying and addressing even minor bugs that may have been missed during testing.

Here are the most widely used tools for automation regression testing: Selenium, TestNG, Appium, BrowserStack, and Jenkins.

These tools help in increasing the overall efficiency, framing the test scripts, and increasing the pace of executing the scripts. However, aiming for 100% automation is not viable as certain tasks need to be done by human testers like designing the test cases.

2.    Select The Right Test Cases

Now that the tests are automated, it doesn’t mean you can run as many tests as you want. Because running the automated tests takes time and effort too. And, then you have to review the failures and maintain the tests.

Therefore, focus on fewer yet efficient test cases instead of having a large number of test cases.

Consider these points while selecting the test cases:

1. Make sure the regression test suite is updated and all the obsolete test cases have been removed.

2. The main aim of an efficient test case is to ensure a wide test coverage, right? Therefore, each test case should aim to cover a wide range of features, user scenarios, and as much of the workflow as possible.

3. Select the test cases that focus on the area where the recent changes have been made in the code or functionality of the application. These areas are more likely to have issues.

4. Prioritize test cases based on their criticality, importance, and chances of regression issues occurring. Focus on test cases that cover critical functionalities, commonly used features, and areas more prone to regression problems.

5. Focus on areas with higher risk or potential business impact and select the test cases considering the risk associated with the changes/updates.

3.    Set Up The Regression Test Environment

Once you have designed and selected the test cases, you need an interface to execute them. This interface is called a test environment which means you create an environment that closely resembles the actual environment where the application will be deployed. It includes setting up the necessary infrastructure, configuration, tools, and data to perform the testing.

Every test environment is set up by bringing together the combinations of the following elements:

• Test data
• Software to be tested
• Network configuration
• Testing devices
• Operating system
• Database and testing server
• Test automation frameworks and tools
• Software for system and application interfacing
• Documentation, including test scenarios, user manuals, and business/customer requirements

The ideal approach to setting up a test environment is to use actual device-browser-OS combinations once the software is ready. To simplify the process, consider automating integration and testing using a CI/CD pipeline tool like Jenkins. This helps streamline the setup and testing procedures for better efficiency.

4.    Defect Management

Let’s imagine, you add a new feature in your food delivery app. It has some errors but the development team resolves those issues. Now, those issues are fixed, and the new feature is functioning smoothly but it caused some issues in an existing feature that was working fine previously. So, these defects are called regression defects.

Regression Defects occur when changes/modifications to the code cause previously working features to stop functioning properly.

Defect management is a whole process of defect identification, categorization, fixing, and analysis.

1.     Identification

To effectively manage defects, you need to first identify them.

• Having a centralized system accessible to all testers is essential for identifying and categorizing defects. When selecting defect management tools, look for features that support this process

• Refrain from relying solely on emulators or simulators, as they may not provide completely accurate results. Testing on real browsers and devices is necessary to evaluate the testing process effectively.

• Testers need to test the application in real user conditions and real devices to detect all the possible bugs.

2.     Categorization

Once the defects are identified, categorize them to efficiently address the issues. You can categorize them by these factors:

• Their stages
• Active (under investigation)
• Test (fixed and ready for testing)
• Verified (Re-tested and approved by QA engineer)
• Closed (completely resolved)

•  Their severity levels 
• Low (minimal impact on the system)
• Minor (causes some unexpected behavior but doesn’t disrupt the system)
• Major (can cause significant parts of the system to fail)
• Critical (capable of triggering a complete system shutdown)

• Defect type

• Cost of fixing

3.     Fixing

Now, that you have identified and categorized the bugs, you have to address and efficiently fix them.

• Allocate: Assign each bug to the respective developer responsible for the software. Create a schedule to address all defects based on their priority.

• Fix: Developers work on fixing the identified bugs, and managers track the process.

• Report: Once the defects are fixed, developers provide reports to the manager and mark their status “closed”.

4.     Analysis

Once you have fixed the defects, it’s important to analyze the defects enhance your understanding of defects, implement improvements, and strive for higher-quality applications.

• Collect critical error data and corresponding corrective actions

• Share the lessons learned with relevant teams to improve future development practices and resolution methods, aiming to prevent defects or fix them faster

• Self and peer reviews are valuable tools for learning and motivation

• Implement defect analysis as a mandatory part of the software testing process to foster a better-functioning team focused on achieving zero defects

However, the most prominent way to prevent regression defects is to keep these defects fixed before release by conducting regular regression testing during your release cycles.

5.    Use Tools and Frameworks

When you have to re-run the tests repeatedly and do the same monotonous job, you need to use tools and frameworks. Here are some popular ones that can help you streamline and automate the regression testing process:

• Selenium is a popular open-source tool used for regression tests. It has cross-environment, OS, and browser support and is compatible with multiple programming languages.

• tsetRigor has this “No Code” approach and uses the English language as the medium of instruction. It claims to increase the speed automation significantly by 15x when used in full force and gives high test coverage with low maintenance.

• Ranorex Studio is an all-in-one solution for testing web, desktop, and mobile apps and focuses mostly on efficiency when it comes to automation regression testing.

Best Practices for Effective Regression Testing

1. Implement a regression framework from the start of the project and keep the test suite regularly updated to reflect any changes to the application.

2. Timely check and analyze the user experience on your application and make a list of the most widely used functionalities. Focus on covering these functionalities while designing the test cases. And, updated these test cases regularly.

3. As said, automation is non-negotiable. Automate regression tests to significantly reduce the time and effort required for testing. And not only that, it will also increase the test coverage and improve test accuracy and efficiency.

4. It’s good to have the QA team involved in code reviews. This helps them understand which parts of the code have been changed, which is useful for making continuous updates. It also helps them identify areas that might be affected by regression issues.

5. In addition to code reviews, QA can work closely with developers while they’re creating new modules. It will allow the QA team to take notes and plan their regression tests effectively, ensuring comprehensive coverage for the release.

Enhancing Regression Testing with LambdaTest

Regression testing avoids any adverse impacts of code changes. LambdaTest is a powerful tool that enables effective regression testing on top of multi-featured functionalities.

From parallel test execution, screenshot sharing, compatible integration with Selenium WebDriver, seamless CI/CD pipeline integration to comprehensive collaboration and reporting, the platform has popularly aided regression testing.

Conclusion

If regression testing is conducted without understanding its true purpose and benefits, regression testing can be frustrating, time-consuming, and not very valuable. However, by using the right mix of processes, tools, and human analysis, regression testing can provide valuable insights. Therefore, a solid strategy is important.

By incorporating the above tips and best practices, teams can create an effective regression testing strategy.