How Regression Testing Helps in Protecting Enterprise Software

Regression testing aims to uncover if changes like new features, defect fixes or configuration updates end up breaking existing functionality in the software.

In other words, it makes sure newly added code doesn’t trample over working older code.

The goal is to check that the software is still working correctly and major functionality has not been damaged by changes.

Of course, minor regressions and bugs do creep in over time. Regression testing aims to uncover these early so they can be addressed.

So regression testing provides confidence that the software’s major capabilities are still operational after modifications are done.

Think of regression testing like regularly visiting a doctor for a full body medical checkup. The doctor examines you thoroughly to ensure all your vital organs are functioning normally so you remain healthy.

Similarly, regression testing thoroughly scrutinizes a software application to certify it is still “healthy” after undergoing changes.

Key aspects of regression testing include:

• Testing unchanged functionality – the focus is on re-running test cases related to features that have not been modified to see if they have been impacted.
• Catching regressions from indirect side effects – verifies that the code enhancements or bug fixes didn’t inadvertently affect other parts of the application and cause unintended consequences.
• Protecting core functionality – guards against changes that alter expected behaviors, performance or outputs of critical existing features.
• Re-executing existing test cases – involves re-running test cases that have already been executed, often repeatedly across multiple iterations or releases.
• Testing after any source code change – should be conducted whenever updates of any type are made to application source code, including enhancements, patches, configuration changes, etc.
• Validating application stability – checks that the system functions, integrates, performs, and operates as expected to remain stable through ongoing development cycles.

Now you may be wondering if regression testing is really that crucial for software projects.

What if you skip it to save time and effort? Will it matter that much?

Well, think back to the last time you upgraded to a new version of your favorite software application. update introduced some nasty new bugs that drove you crazy.

Chances are those painful regressions could have been detected and fixed early using regression testing.

Here are 5 key reasons why regression testing is critically important:

1. Prevents New Bugs in Existing Features

New code changes can interact in unexpected ways with previous code and end up breaking functionality that worked earlier.

Regression testing simulates real-world software usage and uncovers such damaging defects before they impact customers.

Imagine code change triggers an error in the payment processing module of an ecommerce site right before Black Friday. That could result in massive lost revenue and angry customers unleashing their fury on social media.

Proactive regression testing provides safeguards against such catastrophic regressions.

2. Reduces Project Risks and Costs

Bugs that slip undetected into production can lead to enormous costs in downtime, data loss and manual repairs.

Case studies have shown bugs found in late stages of development can cost upto 100x more to fix than ones detected early through regression testing.

By exposing bugs and integration issues early, regression testing significantly reduces project risks and lowers long term costs.

3. Builds Customer Confidence

Quality conscious customers have low tolerance for software defects and loss of service. Emails from dissatisfied users complaining about regressive bugs erode trust in the product.

Rigorous regression testing delivers stable software with minimal disruptive defects. This results in confident customers who continue using and promoting the product.

4. Facilitates Change Management

Software development is a continuous evolution. Designs get refactored, new technologies adopted and features augmented.

Regression testing allows developers to make such changes without worrying about inadvertently breaking something else along the way.

With a solid regression testing foundation, you can build, innovate and improve your software boldly and rapidly.

5. Results in Higher Quality Software

At its heart, the biggest benefit of regression testing is it results in stable high-quality software with minimal defects.

By thoroughly validating expected functionality, it adds a vital quality gate before releasing updates.

Higher quality translates to reduced outage risks, lower maintenance costs and increased customer adoption.

So in summary, regression testing delivers confidence, reduces risks, lowers costs and enables innovation – all of which are competitive advantages in business.

Now that you’re convinced regression testing is worth investing in, let’s look at when it should occur:

• After Bug Fixes – Regressing bugs quickly reveals if the fix was complete or caused any ancillary issues.
• When Adding New Features – Validate that newly added capabilities don’t step on existing functionality.
• During Integration Testing – Verify feature interactions still work when integrated together.
• After Infrastructure Changes – Hardware, OS or environmental changes can impact software behavior.
• During Final Release Testing – This critical last check for regressions guards against disruptions when going live.
• Periodically in Maintenance – Incremental regression tests help proactively find issues introduced during ongoing upkeep.
• In Agile Sprints – Focused regression suites prevent sprint changes from damaging existing capabilities.

Essentially, regression testing provides useful quality feedback whenever code changes occur. The more frequent, the better!

Different Types of Regression Testing

Regression testing approaches primarily differ based on scope and extent of test coverage. Let’s examine popular regression testing types:

Full Regression Testing

This is the most comprehensive approach. As the name suggests, full regression testing validates the entire application thoroughly in an end-to-end manner.

All the test cases in the regression test suite will be executed to check for regressions. This offers maximum coverage but takes considerable time and effort.

Full regression testing should be used for major releases, infrastructure changes and high risk situations.

Partial Regression Testing

Rather than testing end-to-end flows, partial regression focuses only on modules impacted by code changes. Related downstream functionality may also be covered.

Only targeted test cases related to the changes are executed unless serious issues emerge necessitating wider coverage. Partial regression testing is faster but has limited coverage.

Progressive Regression Testing

Progressive testing deals with validation of new functionality added to the system. New test cases are written to check the integrated behavior of new capabilities with existing features.

The emphasis is on validating the new parts while also determining if they adversely influence older functionality. This focused approach is useful during enhancements.

Selective Regression Testing

This approach selectively picks a subset of tests from the entire regression test suite and executes only those. High priority test cases covering critical functionality are chosen based on risk analysis of change impact.

The goal is to gain confidence quickly by validating core functionality without exhaustive testing. Careful test case selection is key to this approach.

Retest-All Regression Testing

As the name suggests, in retest-all regression the entire test suite is re-executed to check for regressions. It is similar to full regression, but no new test cases are created.

The goal is to definitively validate previously tested behaviors are unaffected rather than cover new functionality. Significant effort but offers maximum chance of catching regressions.

Step-by-Step Guide to Regression Testing Process

Now let’s walk through the end-to-end regression testing process:

Step 1: Determine Scope and Coverage

First assess the scope and coverage you need based on analysis of changes, availability of resources and project timeline constraints.

Changes to core functionality require thorough regression testing for risk mitigation. Lower priority peripheral changes may need less coverage.

Step 2: Select Test Cases

Next pick relevant test cases, test data and test scripts required toregression test the scope determined earlier.

Reuse existing test artifacts as much as possible. Add or modify ones for testing new functionality or variations in flows.

Step 3: Prioritize Test Cases

Review all selected test cases and prioritize them for execution based on importance of the underlying functionality and impact criticality.

For example, high priority for login page, medium for search results and low for newsletter signup.

Step 4: Execute Tests

Run the regression test cases in order of priority from high to low.

Log results for all test executions. Record details like overall elapsed time, pass/fail ratio, number of bugs etc.

Step 5: Report on Testing

Analyze results at the end of testing. Document executive summary highlighting scope, quality metrics, test coverage, defects found and recommendations.

Step 6: Retest Bug Fixes

For any bugs found, log defects with steps to reproduce, screenshots etc. Fixes by developers need to be re-tested to confirm issues are resolved.

Step 7: Automate Regression Suite

Automating repetitive test cases improves efficiency of future regression cycles.

Step 8: Analyze Results

Analyze regression test results to identify weak spots in test coverage and frequently failing areas needing concentrated quality improvement.

Discuss gaps, mitigation strategies and schedule improvements with stakeholders.

Top Regression Testing Tools

Automating repetitive regression test cases is highly recommended. This frees up QA resources and enables frequent regression cycles.

Here are some of the top open-source and commercial regression testing tools:

Selenium

The open-source web testing tool Selenium is the most popular solution for automating browser-based regression test cases. Its flexibility and active ecosystem of users makes it a great fit for regression testing web applications.

Katalon Studio

Katalon Studio simplifies creation and execution of automated regression test scripts across API, Web, mobile and desktop apps with minimal coding. It also provides built-in integration with CI/CD tools.

TestComplete

TestComplete allows you to record test steps, customize scripts and add checkpoints to automate regression testing desktop, web and mobile apps. Reusable keyword-driven tests, database integration and comprehensive reporting make test automation highly productive.

Ranorex

Ranorex offers a robust automation framework specifically optimized for GUI testing of desktop, web and mobile apps. Smart object recognition, reusable code modules and extensive integration with CI/CD pipelines makes it a powerful regression testing tool.

Tricentis Tosca

Tosca provides a model-based automation approach for optimizing regression test cases covering critical business risks. Its dashboards provide insights into regression test coverage and results across sprints or releases.

QASE

QASE is a tester friendly test management platform with capabilities for test case management, execution tracking, version control and integration with automation frameworks.

TestProject

TestProject is an open-source test automation framework that provides capabilities to record, customize, replay and report test cases across web and mobile apps. Add-ons like test scheduling, CI/CD integrations and real time test dashboards make it ideal for accelerated regression testing.

Best Practices for Regression Testing

Here are some key best practices recommended by industry experts:

Start Early

Do not keep regression testing for the late stages. Start right from the initial sprints or builds so defects can be detected and fixed early.

Prioritize Correctly

Classify test cases based on criticality and execute high priority ones first. Do not randomly select test cases for execution.

Leverage Automation

Automate time-consuming repetitive tests to improve efficiency and frequency of regression cycles.

Facilitate Reuse

Facilitate reuse of existing test cases and scripts when adding new checks using techniques like keyword-driven testing.

Complement Exploratory Testing

Combine scripted regression tests with exploratory charter-based techniques for greater coverage.

Use Checkpoint Metrics

Use checkpoints in test cases to detect side-effects like software crashes, memory leaks etc.

Simplify Maintenance

Design modular test cases following the DRY principle so they are easier to maintain as the application evolves.

Integrate with CI/CD

Embed regression test suites into CI/CD pipelines to enable early detection of regressions.

Analyze Results

Analyze regression test results frequently to identify problematic areas needing concentrated quality improvements or additional test coverage.

Inspect Trends

Inspect trends in regression cycles to prioritize test suite maintenance and enhancements to maximize ROI.

Pros and Cons of Regression Testing

There are a number of key advantages to regression testing:

• Catches Bugs Introduced by New Code Changes – detects bugs/defects that may have unknowingly been inserted into unmodified functionality when changes are made elsewhere.
• Confirms Behavior of Existing Features – provides confidence that core components of the system still behave as originally intended after modifications are completed.
• Protects End User Experience – guards against inadvertent impacts to usability, functionality, workflows, performance, and outputs visible to users.
• Enables Faster Releases – allows for more incremental updates and enhancements to be released more frequently since each change is thoroughly regression tested.
• Reduces Meta-Defects – minimizes more pervasive or difficult bugs that may emerge from problematic changes impacting broader application.
• Promotes Application Stability – contributes to ongoing stable state of application through cumulative changes.
• Iterative Development Accelerator – essential practice for incremental Agile development models allowing faster delivery of updates with contained risk.
• Leverage Test Automation – repeating manual test execution is slow and expensive, so automating regression testing is key for productivity.

However, there are also some downsides to consider:

• Time Consuming – re-running full regression test suites manually requires significant time and human effort.
• Repeated Testing – continually re-executing the same test cases can be boring and undermine tester motivation.
• Release Velocity Impacts – extensive regression testing can extend release cycles and delay delivery of updates.
• Test Suite Maintenance – suite needs to be constantly reviewed and updated as application evolves over time.
• Tooling Dependence – manual execution is unrealistic so test automation tooling becomes critical dependence.
• Test Coverage Challenges – efficiently balancing breadth and depth of scope covered is difficult.

Overall, the benefits seem to far outweigh the downsides for most teams. Having a regression testing practice in place is foundational for validating application stability through ongoing enhancements and change management.

Regression Testing vs. Retesting

There is often confusion between regression testing and retesting:

Retesting focuses on validating correctness of newly developed functionality, bug fixes or enhancements. New test cases are written to test the changed portions. Regression testing re-runs existing test cases to check if changes broke previously working functions. The focus is on existing rather than new code.

Retesting gives confidence in modifications while regression testing ensures stability of overall system behavior. In short, regression testing aims to catch unintended side-effects of changes on the entire system while retesting focuses only on the changed portions.

Regression Testing Example

Let’s look at a real-world example to understand the importance of regression testing:

The Acme Online Shopping application has a working coupon code feature that allows customers to enter promo codes during checkout to get discounts.

The development team now needs to enhance this feature by allowing coupon codes to be restricted to specific customer groups.

They code the changes to apply restrictions during coupon creation and add a check during checkout validation. Unit testing of the new logic works fine.

The updated version passes integration testing and is released.

But after go-live, customers complain that regular coupon codes no longer work for anyone!

On investigation, the team finds that while applying restrictions in the new change, they inadvertently broke the coupon validation flow for old unchecked coupons.

This regressive bug went uncaught as existing positive test cases were not re-run to check the impact of the change.

If comprehensive regression testing was done, they could have detected the issue early and fixed it before impacting customers.

This example illustrates how even a small code change can introduce regressions in previously working functionality if regression testing is not performed.

Conclusion

In essence, regression testing aims to provide a safety net during software evolution.It prevents our desire for continuous improvements from damaging existing functionality. Leveraging the right strategy optimizes allocation of regression testing efforts and provides faster feedback.

Integrating regression testing into the CI/CD pipeline improves release quality significantly. And automation acts as a force multiplier allowing frequent regression cycles.

By proactively finding and addressing defects before they reach users, companies build customer trust and accelerate growth. So do your part in the epic battle against bugs! Embrace regression testing as an ally and vanquish disruptive defects before they ruin software functionality.

In essence, regression testing aims to provide a safety net during software evolution.It prevents our desire for continuous improvements from damaging existing functionality. Leveraging the right strategy optimizes allocation of regression testing efforts and provides faster feedback.

Integrating regression testing into the CI/CD pipeline improves release quality significantly. And automation acts as a force multiplier allowing frequent regression cycles.

By proactively finding and addressing defects before they reach users, companies build customer trust and accelerate growth. So do your part in the epic battle against bugs! Embrace regression testing as an ally and vanquish disruptive defects before they ruin software functionality.

TAV Tech Solutions is a leading software development company specializing in offering a complete range of software service and technology solutions across industry verticals. Regression testing makes certain that a software is free of bugs post incorporation of new updates on the platform. TAV Tech Solutions is backed by some of the best developers in the industry assisting businesses with seamless regression testing. The QA team conducts a series of tests to ensure all the features and functions of a software are working properly.