Regression Testing Definition – Test Cases, Tools, and Methods

Introduction

Do you know the meaning of regression testing? As a software developer, knowing this vital concept in the software development process is important. This type of testing helps guarantee that software changes don’t negatively affect existing features, making it an essential factor in preserving the stability and dependability of software products.

In this blog, we’re going to walk you through in detail related to regression testing, its importance, and its benefits, types, tools and anything else you need to know will all be covered in detail. After reading this post, you’ll understand the regression testing concept and its significance in software development. Let’s get started!

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What exactly is Regression Testing?

Regression testing is a type of testing used to ensure that a software change won’t affect the product’s current functionality.

This is performed to ensure that any added features, bug fixes, or modifications to existing features don’t affect how well the product functions.

Regression testing is a type of software testing where test cases are repeated to see if the application’s previous functionality is still operational and whether the latest changes have not resulted in any new defects.

When there is a significant change in the original functionality, even in only one bug fix, regression testing can be done on a new build.

Regression is the process of testing the application’s unaltered components again.

The core of regression testing is testing the same code or app multiple times. As a developer or tester, this process can be used to guarantee that any changes made do not disrupt the existing functioning of the program.

Example of Regression Testing

Let’s take a look at the case to understand regression testing better. Imagine, A product X whose functionality includes sending emails when clicking the Confirm, Accept, and Dispatch buttons.

There are some problems with the confirmation email, and some programming changes are performed to address them. To make sure that the modification in the code has not affected them, it is necessary in this case to test not only the Acceptance and Sent emails but also the Confirmation emails.

Regression testing is independent of any programming language, including Java, C++, C#, etc. This technique of testing is used to check the product for updates or revisions. This verifies that any product alteration does not impact its current modules.

Regression testing verifies that the fixed bugs and newly added features do not create any problems in the previous working version of the Software.

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What are the advantages and disadvantages of Regression Testing?

The followings are the advantages and disadvantages of Regression Testing:

• Advantages of Regression Testing

1. Verify that any alterations to code do not have an unfavorable effect on other functions.
2. Acts as a security measure during the assessment.
3. Uncomplicated to learn, comprehend and assess.
4. Enhances the Product’s quality.
5. Guarantees that bug fixes or improvements don’t influence the present characteristics of the Product.
6. Automated software can be employed for this testing.
7. Ensuring that previously mended issues don’t re-emerge.

• Disadvantages of Regression Testing

1. Making even a minor alteration in the code could lead to problems in existing functionality, requiring a small change.
2. As automation is not employed for this testing, executing the test cases repeatedly will be an arduous and lengthy process.
3. Regression testing without automation can be very time-consuming.
4. Necessary to implement each small alteration in the code.
5. A highly repetitive task can have a negative impact on the agile sprint.
6. Complex test cases must be created.

Regression testing can help you produce reliable goods and reduce risk, but the process itself is time-consuming. So, you must consider both perspectives before making a choice. Let’s look at some of the challenges linked to this type of testing.

Top Regression Testing Challenges 

• High Upfront Cost:

Setting up a regression testing environment and creating a comprehensive test suite can be costly, especially for large or complex applications. This can be a barrier to entry for some organizations, particularly smaller ones with limited budgets.

• Testing Approach:

Regression testing success depends on choosing the right testing strategy. Even if you have knowledgeable personnel and equipment at your disposal, you will still have trouble if you don’t have a strategy for when and how to approach or carry out regression testing.

• Enormous Scope and Coverage:

The development of the suite was not without difficulties. In the QA environment, the testing suite and the coverage of functional scenarios should be current.

Checking the regression suite in the QA instance or test environment in between build releases ensures that crucial cases are addressed. Any missing or unrecognized features or functions should be included in the suit. If any flaws are discovered, they shouldn’t be added to the suite until they are corrected. We will be able to list the functionality to be included and excluded in the test suite and potential scenarios as we examine it.

• Complexity:

The number of test cases increases as you go from the first build to the second and so on. The regression test suite will grow in complexity as a result. You will constantly need to test both the new and the old cases.

Now that we have covered the basics of regression testing, it’s time to look at how to implement it.

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How to Perform Regression Testing?

An effective regression testing suite ensures your software works accurately after any changes or updates.

Here are five steps to creating an effective regression testing suite:

Step 1: Identify Alterations to Source Code

In this step, we identify any changes made to the source code, such as modifications and optimizations, and the impact they have had on the product’s existing features.

Step 2: Prioritize Changes & Product Requirements

We then prioritize all product requirements and code alterations by using the appropriate tools and test cases to align with the test process.

Step 3:  Select Test Cases to Re-execute

Using the modified module, we select test cases for re-running, without needing to test the whole test suite. Afterward, these test cases are identified as either reusable or obsolete; the reusable cases are chosen for regression testing, while the obsolete ones are excluded from future testing cycles.

Step 4: Analyzing Factors to Evaluate Test Case Execution Time

Examining factors such as test data readiness, test case design, etc. can help ascertain the time taken for test case execution.

Step 5: Distinguish Automated & Manual Test Cases

It is important to differentiate between automated and manual test cases. Automated test cases are faster and the test scripts can be reused multiple times. This allows for efficient regression testing.

Step 6: Prioritize Test Cases

In this step, we rank the collected test cases based on their significance (high, medium and low). Priority is given to the test cases of urgent importance, followed by those of medium and low significance. Priorities are assigned according to the usefulness of the product and user involvement.

We prioritize using the following criteria:

• Priority 0: Essential test cases that cover key features
• Priority 1: Features of importance, but not as essential
• Priority 2: Test cases that involve technical complexities.

Step 7: Schedule & Execute Test Cases

For the last step, plan and carry out test cases. Automated or manual testing can be used to check if the product does what it is supposed to do, with the help of tools such as Selenium, IBM Rational Functional Tester, Watir, etc.

Different Types of Regression Testing 

1. Corrective Regression Testing: 

When your application’s source code has not changed, corrective regression testing is a good choice. Instead of creating new ones, you will evaluate the existing functions and the test cases that go with them in order to determine whether the current system is operating as intended.

2. Progressive Regression Testing: 

As particular changes are made to the program and fresh test cases are created, this kind of regression testing produces results that are more meaningful. By conducting this testing, one may make sure that there are no components in the older version that might be vulnerable to the newest and upgraded version.

3. Selective Regression Testing: 

As the names suggest, in selective testing, the test coverage is limited to a chosen subset of already-created test cases. Therefore, you merely test the selected components rather than the entire system again.

4. Partial Regression Testing: 

The purpose of partial regression testing is to ensure that the code continues to function properly even after changes have been made and the unit has been combined with previously written or unaffected code.

5. Complete Regression Testing: 

This type of regression testing is performed whenever the code is changed across multiple modules and/or when it is unknown how a change in one module will affect changes in other modules. To look for any modifications brought on by the modified code, the entire product is regressed.

6. Retest-All Regression Testing: 

It is a challenging testing method. It necessitates that all system details be checked back to their original sources. It examines each little modification that the program has experienced since it was created. The most frequent retest scenario happens when other regression tests have been unable to pinpoint the problem, as development teams believe the problem predated the most recent code changes.

Now that you understand the various regression testing services the QA team can perform, let’s take a deeper dive into the world of automation and analyze some of the most popular regression testing tools available today.

Best Regression Testing Tools

1. Selenium

One of the best tools for regression testing is Selenium, which you may have heard of. As a result, when it comes to cross-platform or browser-based regression testing, selenium may be one of the first names that come to mind. The program offers automated test scripts using datasets and is ideal for in-depth quality assurance testing on a big scale.

2. Katalon Studio

A complete solution for regression automation testing is offered by Katalan Studio. It attempts to simplify and open up the testing process to new testers. Your one-stop shop for online services, web applications, and mobile app testing is Katalan Studio. In addition to all of these, the tool offers a reporting and advanced analytics function.

3. TimeShiftX

By minimizing the amount of time spent on testing, meeting deadlines, and lowering the number of resources needed, TimeShiftX gives businesses a significant edge while still delivering highly reliable software.

4. IBM Rational Functional Tester

IBM developed Rational Functional Tester, or RFT, a testing automation tool that supports several types of testing, including regression testing, functional testing, and data-driven testing. The tool is useful for testing a variety of programs, including web applications,.NET, Java, SAP, emulator-based programs, etc. RFT also makes the testing procedure simpler for testers everywhere.

5. Apache JMeter

For monitoring the effectiveness of test cases, Apache developed Apache JMeter, an open-source regression test automation tool. Java programming is used exclusively in the creation of the software. JMeter’s primary capabilities include the ability to execute load and performance tests, measure service performance, and offer an end-user regression testing platform.

6. AdventNet QEngine

AdventNet QEngine is a paid software that facilitates regression testing for web and desktop applications. It provides capabilities like test management, automated test generation, and execution.

7. Subject7

A popular cloud-based enterprise-level regression automation testing platform for desktop, web, and mobile apps is called Subject7. For programs prepared for public, private, and hybrid clouds, the technology offers high-scale parallel execution. Regardless of whether you view the tool from a technical or financial angle, it excels on each of these criteria.

8. Virtuoso

Virtuoso brings an end to manual and time-consuming tasks associated with regression tests, by allowing you to create bots that search your application’s DOM and build an accurate picture of each element. This data is then used by a Machine Learning algorithm to detect any unexpected changes in the tests, freeing up testers to concentrate on finding bugs.

Regression tests are created in plain English, using Natural Language Programming, so they are fast and accessible. What’s more, tests can be written once and reused across multiple browsers and devices – providing the fastest authoring experience.

Virtuoso is a revolutionary, AI-augmented testing tool that allows you to ensure that your regression testing is done in-sprint, and is easily integrated with your CI/CD pipeline.

9. Cerberus Testing

It is an open-source platform providing support for regression testing of web applications. It offers capabilities such as test management, test automation, and integration with popular testing tools like Selenium.

10. Testsigma

Testsigma is a cloud-based platform providing support for regression testing of web and mobile apps. It provides AI-powered test creation, test management, and integration with tools like Selenium and Appium.

Knowing the tools for regression testing is important, but knowing the best practices is essential to getting the desired results. Let’s focus on best practices for regression testing that can help you ensure the accuracy and effectiveness of your tests.

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Best Practices for Regression Testing

1. Stay on Top of Regression Suite

To stay up-to-date with the regression suite, assess the functional and non-functional requirements. Make sure to prioritize and execute the valuable test cases first.

2. Track Every Change Closely:

In software development, change is inevitable. It is important to have a thorough understanding of any modifications. Encourage collaboration between developers and testers to always know the newest version and any sudden changes. This can help to plan to test efficiently and stay on track with product releases.

3. Assigning Grade to Test Cases:

To be successful with regression testing, it’s important to grade all the test cases. Compare and track the business impact of different platforms, and based on that evaluation, set high, medium, and low priority for various test scenarios. This will help in recognizing, distinguishing, and identifying diverse obstacles as well as conducting effective testing with respect to the requirements.

4. Understanding the Scope of Testing:

Prior to initiating the regression testing process, it’s essential to understand its scope. As each testing project can vary in terms of scope, time, and goals, comprehending the differences in scope will enable you to plan your regression cycle execution better.

5. Automatically Run the Correct Test Cases:

Only when you use automation effectively can you gain a competitive edge. In order to determine which test cases may be automated and which ones cannot, you must first make this determination. Finally, automating appropriate test cases will boost your output and free up your valuable time.

6. Track ROI (Return on Investment): 

It is essential to assess the RoI of your regression testing campaigns. To ensure this, QA teams must keep an eye on RoI through the analytics and reports provided by automated tools. Doing this will help to understand the actual situation and spot areas that require improvements.

Now that you understand the best practices that QA managers should follow for effective regression testing, it is important to understand the difference between regression testing and retesting. While there is often confusion between the two in the testing community, let’s take a closer look at their key differences in our next section.

Regression Analysis vs. ReTesting

Regression testing and retesting are two important software testing techniques that differ in their purpose, scope, and timing.

Here are some key differences between the two:

So far, we have taken a comprehensive look at regression testing from every possible angle. We have also understood the difference between it and retesting. The next step is to understand the role of regression testing in following an agile methodology.

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Agile Methodology and Regression Testing

As you know, agile methodology is based on incremental and iterative approaches. You develop software or a product by breaking it down into short iterations called sprints. With each sprint, the source code changes with additions or updates to new features. This is where regression testing comes in.

Agile teams should begin preparing their regression test suite from the earliest stages of product development and continue to use it until the final deployment. In agile methodology, regression testing can be done in two ways:

• Sprint Level Regression: 

Sprint Level Regression is typically performed for new features or improvements that were completed in the most recent sprint. The test suite’s test cases are chosen based on the newly implemented functionality or improvements.

• End-to-End Regression: 

End-to-End Regression consists of all the test cases that need to be repeated in order to thoroughly test the product’s fundamental functionality.

Agile uses brief sprints, and as the project progresses, it becomes increasingly important to automate the test suite. In addition, test cases must be run again quickly. The execution time and defect slippage are both decreased by automating the test cases.

Conclusion

Regression testing is an important part of software development and maintenance. Regression testing is one of the essential aspects since it ensures that every code change, no matter how small or significant, has no negative effects on previously implemented functionality.

There are many automation tools available for automating regression test cases; however, the project requirements should be taken into consideration when choosing a tool. The Regression test suite needs to be updated frequently, hence a tool should be able to do this.

But if you’re still interested in it or want to test for regression in your products, get in touch with us right away. We would be pleased to use our experience to help you through the testing process and smooth the way for your development process.

With that, we will conclude this discussion with the hopes that the matter will be much more clearly understood moving forward.

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