As a developer, there are occasions when just a minor adjustment can completely sabotage a software project. The good news is that regression testing can assist you in preventing any errors that could put your product in danger. 

Although practically every firm uses regression testing, each team may have its own protocols and methods.  The effectiveness of the most recent code added to or modified on the application must be assessed using regression testing methods. By doing this, all parties involved are kept well informed regarding the nature of their product. For instance, during the early phases of the deployment cycle, you can identify and address bug problems.

Why is regression testing important? is no longer a relevant question. Business executives prefer to do things correctly from the start. 

This blog serves as a basic guide for businesses looking to implement a regression testing strategy. It helps teams develop their test strategy by enabling them to delve further into the gaps in their present regression testing method.

1. Regression Testing

Regression testing is a sort of software testing that confirms an application still operates as intended following any code updates, revisions, or enhancements. The team must undertake regression testing as the application evolves by adding new features to ensure that the existing features function as intended and that no defects are triggered by the new feature (s).

Regression testing strategies will be covered in this post, along with the ones to employ based on your team’s working style.

2. Why Is Regression Testing Necessary?

A software application is immediately altered by new (functional, performance, or even improved security) enhancements, alterations to already-existing features, bug patches, and updates. The services it uses from third parties to provide functionality through its interface have an indirect impact on it as well.

Verification is necessary for all planned and unplanned changes to the application’s source code. The effects of changes to external services used by the application should also be confirmed.

Teams must verify that the new application component performs as intended and that the modification had no negative effects on the program’s other portions.

The team uses a thorough regression testing technique to detect regression issues, which are then fixed and retested to guarantee that original bugs are not present. 

3. Example of Regression Testing

Let’s rapidly comprehend using the login capability as an example.

• Using their login and password or their Gmail account via Google integration, a user can log into an app.
• Users can now log into the app using their LinkedIn account thanks to the addition of a new feature called LinkedIn integration.
• Verifying that other login methods continue to work is just as important as making sure the LinkedIn login works as planned (Form login and Google integration).

4. Difference between Regression, Smoke and Sanity Testing

In testing, the terms smoke, sanity, and regression are considered synonymous, which is incorrect. These terms vary not just in terms of the scope of the application but also in terms of the timing of execution.

4.1 How do smoke tests work?

At the beginning of a new build, smoke testing is done. The main objective is to determine whether the build is sufficient to begin testing. Examples include the ability to access a website by merely typing its URL or the ability to run an application following the installation of a new executable.

4.2 Sanity testing: what is it?

Surface-level testing on recently installed settings is known as sanity testing. Before being transferred to User Acceptance Testing, for instance, the features are thoroughly tested on staging environments. Another illustration would be to check that the expected components are interactive and that everything appears to be in order overall without conducting a thorough testing.

4.3 How is smoke and sanity testing different from regression testing?

Regression testing goes deeper since it extensively examines the regions that could be impacted in a setting where fresh modifications have been made.

Stable features that have already been implemented are extensively tested frequently to confirm their accuracy in the face of both deliberate and unintended modifications.

5. Methods for Regression Testing

The following categories can be used to classify the techniques:

5.1 Partial Regression Testing

Partial regression testing, as the name implies, is a methodology in which only a small portion of the total regression suite is chosen and tested.

The following logical criteria are combined to produce the subset selection:

Finding the feature(s) that could be impacted by the change led to the cases. 

• instances that are crucial to the business
• the most frequent itineraries

When the team successfully locates the impacted areas and the accompanying test cases using tried-and-true techniques like the Requirement Traceability Matrix (RTM from here on) or any other type of metadata endorsed by the team, partial regression testing works incredibly well.

Partial regression testing is more appropriate in the following circumstances:

• A strong test automation framework is in place for the project, and there are many Unit, API, Integration, and Acceptance tests that are distributed according to the test pyramid.
• The cross-functional team constantly monitors and communicates on changes to the source code.
• Short-term initiatives with limited funds and resources.
• On the project for a considerable amount of time have been the same team members.

5.2 Complete Regression Testing

Many times, the team is required to undertake extensive regression testing to find new issues or issues that have arisen as a result of the modifications, such as when there have been large software updates or changes to the tech stack.

This method involves running the entire test suite every time new code is committed, or at predetermined intervals, in order to find issues. Compared to the other procedures, this one takes a lot more time, therefore it should preferably only be used when necessary.

One must adopt automated testing to enable effective full regression testing in their teams in order to maintain a faster feedback cycle.

6. Best Practices for Regression Testing

Plan your regression testing with a mix of technological and business scenarios to get better testing coverage for your application. Utilize the techniques across the Test Pyramid.

6.1 Test Data 

To quickly generate test data across many test environments, we should take advantage of automation. We must make sure that the updated feature is assessed using both the old and the new data. For instance, a new field added to a user profile should function consistently for both already-existing and freshly created accounts.

6.2 Production Data

In order to find problems that might have been overlooked during the initial delivery, production test data is essential. When it is practical, recreate the production environment to find edge cases and include those in the regression test suite.

Utilizing production data isn’t always practical and can result in non-compliance problems. Teams routinely hide or mask sensitive information from production data and use the information to meet the need for on-the-ground scenario analysis.

6.3 Test Environments

If you have numerous environments, we should make sure that each one of them runs the programme correctly.

6.4 Getting a Fresh Perspective

When a new member of the team was brought on while the work was already underway, they would thoughtfully inquire about the long-forgotten stable characteristics. In order to gain a pure and comprehensive view of testing, I also prefer young guns to be a part of my regression team.

6.5 Automate 

Automate the regression test suite. Create supporting systems to use the team’s downtime to construct automated tests, or if you don’t have the budget, wonderful. It is sufficient to begin by automating the most frequently used procedures or business-critical scenarios. Start this task and progress slowly.

To be able to execute certain automated regression situations, either tag or annotate your automated scenarios according to the feature or group them into the proper folders. Regardless of the fact that automated test execution is quicker, sequential execution won’t scale as test environments and combinations increase.

To satisfy scalability requirements, concurrent test execution in diverse contexts is necessary. You can run automated tests concurrently across many setups using Selenium Grid and other cloud technologies. The test automation methodology must follow best practices when developing it, and the tests themselves must run quickly and concurrently to get faster feedback.

6.6 Create a sprint plan for regression testing.

It has been observed that automating a regression backlog is time-consuming. Regression testing efforts must always be explicitly taken into consideration when estimating Sprint tasks if you want to continue making progress on this activity. Otherwise, you risk uncovering more issues that add to your technical debt.

6.7 Communicate to each other in the cross-functional Team

Changes are not always communicated or directly tied to client needs. The development team internally keeps the code optimized for reusability, performance, and other aspects. To enable the team to undertake regression testing as necessary, make sure that these source-code adjustments are noted and documented in a bug.

6.8 Scaled Regression Testing

The contributions of numerous teams from various locations go into creating an enterprise product. Regression testing will be carried out independently by the teams, although it cannot only be done thus. In order to test every integrational regression scenario, the teams must also put up cadence structures and procedures.

6.9 Crowdsourced Testing

Crowdsourced testing can assist in identifying brand-new programme defects, such as functionality, usability, and localization issues, hence enhancing the quality of the final product.

6.10 Design a Non-Functional Regression Testing Strategy

Performance, security, usability, and other non-functional aspects must all be evaluated as part of your regression testing strategy in addition to functionality.

A straightforward but efficient method for identifying performance, accessibility, and other degradations is benchmarking test execution results from previous sessions and contrasting them with test execution results following the most recent revisions. The best-functioning applications have either been unable to complete production or have been shelved while successfully launching due to significant flaws in non-functional sections.

7. The Importance of Automated Regression Testing

No matter how you design your applications or what your development technique is, automating regression tests is essential. Whether it’s a small-scale application or a business product, having automated tests will ultimately save you time, energy, and money. 

Let’s examine a few justifications for automating the regression test suite:

7.1 Greater Responsiveness

Software verification performed automatically is much quicker than done manually. Because of the enhanced speed and frequency at which it operates, automated continuous testing in the CI-CD pipeline is a potent strategy for locating regression problems as soon as possible after their introduction.

Examining the test results from each automated suite execution and making real improvements to the product and test suite are equally crucial. Early problem detection will prevent defects from leaking into the most important portions of the application and later testing phases.

7.2 Automated Test Data Generation

The testing teams invest a lot of effort in generating test data before beginning the real testing. Automation helps with both test execution and the quick creation of lots of test data. The functional testing team may use data produced by scripts (SQL, APIs), allowing them to concentrate on testing rather than worrying about the data. Rapid test data creation offers the team with instant test data for testing features like pagination, infinite scroll, tabular representation, and app speed, to name a few.

Insurance and banking are regulated industries with several intricate procedures and nuances. A wide range of test data is necessary to exercise and address the data models and flows. It has been demonstrated that an essential element of effective testing is the capacity to automate test data management.

7.3 Consider scalability

Parallel execution of the automated test suite quickly and effectively satisfies the need for faster feedback. With the proper infrastructure and the requirement of having created a scalable automated test suite, teams may produce test results across a range of settings, browsers, devices, and operating systems.

Cross-browser testing has advanced with the introduction of the Applitools Ultrafast Test Cloud. Using Ultrafast Grid (a component of the Ultrafast Test Cloud), you run your functional and visual tests once locally, and the grid instantly creates all screens for the browsers, devices, and viewports of your choice.

7.4 Upkeep of the Regression Test Suite

Let’s now finish the cycle by ensuring that the associated test cases (manual and automated) are likewise promptly adjusted with every modification and change request to any current portion of the application. The regression suite now needs to include these changed test cases. 

Failure to modify the test cases would result in turmoil among the participating teams. The circus may cause improper testing of the underlying application and result in rollbacks and unexpected features.

In order to maintain the regression test suite, new tests must be added, existing tests must be modified, and unnecessary tests must be removed. The manual and automated test suites ought to be updated to reflect these changes.

8. Challenges in Regression Testing

Following are the major testing problems for doing regression testing:

• With successive regression runs, test suites become fairly large.  Due to time and budget constraints, the entire regression test suite cannot be executed
• Minimizing the test suite while achieving maximum Test coverage remains a challenge
• Determination of frequency of Regression Tests, i.e., after every modification or every build update or after a bunch of bug fixes, is a challenge.

9. Conclusion 

Whether the architecture is monolithic or built on microservices, and regardless of how old or new the application is, a well-thought-out regression testing plan can help your team achieve your QA and software development goals. 

Hire a reliable partner to handle your regression testing needs and improve the responsiveness, adaptability, efficiency, and dependability of your product. Find out more about our services for regression testing. Contact TestDel and learn more about our regression testing services.