Regression testing in agile helps development teams concentrate on new functionality while maintaining stability with every new product increment. Teams use regression testing to make sure that tested software continues to perform after every modification.
In the modern agile process, regression testing plays a very crucial role. In the world of competitive markets, every firm in the software development industry wants to step ahead of others with respect to building a much more advanced software.
Why is Regression Testing Important in Agile Development?
- Agile represents an incremental and repetitive development methodology. With the client demands and the frequent changes evolving around the software in the agile way of testing, regression testing becomes a very important and essential factor in the test life cycle process.
- Agile requires that the developed software undergoes continuous testing and development. Along with incorporating the new feature in the software, the existing functionality of software should not be impacted. Customers should be able to use advanced software without any issues. To maintain software reliability we perform regression testing in agile.
- Regression testing in agile helps to mitigate the risk in the developed software. Regression testing is the means by which we assure the customer the final product delivered meets his expectations. Regression testing is the sub child of agile testing. It helps development teams concentrate on developing the new product while maintaining stability with every new product increment.
- Regression testing in agile gives a clear vision to all the stakeholders in the business on the delivered software post implementing the code changes. Regression testing in agile ensures the code changes done have not introduced any bugs in the software.
- Regression testing in agile is performed whenever there are bug fixes, requirement changes, system performance issues. Regression testing also determines the performance of the overall system. With the continuous integration in agile aiming at continuously delivering an efficient product, regression testing stands important to be performed in every release.
- Complex software development in agile requires both efficiencies in testing and quality to ensure any code changes do not impact existing features. Regression testing in agile forces continuous improvement in the application through the testing cycle.
Benefits of Regression Testing
Regression testing in agile is the key aspect of software testing. Let’s discuss 4 surprising benefits of regression testing in agile:
- Test coverage - Regression testing ensures more test coverage as it aims to execute test cases for all the features of an application.
- Resolve the defect - Regression testing, in agile, when done properly - lets the teams know in advance about a defect in the software. This helps the developers to resolve the defect and prevent incidents on production.
- deliver high-quality software - Regression testing in agile helps to deliver high-quality software to the customer by ensuring system stability while new features and bug fixes are added to the application.
- Cost-effective - Automating regression tests benefits the firm to keep the cost low by minimizing the team size. Resources can focus on more important tasks.
For any upcoming sprint cycle, the regression test suite of the previous cycle is readily available for the test execution phase. Such software testing generates high ROI (Return on Investment) and is less time consuming since the entire testing is executed via automated tests.
Building a Regression Testing Strategy for Agile Teams
It's all about changes and making differences in requirements even in the future with better development phases. The main objective of agile testing is to deliver the product with minimal functionalities.
To perform smooth regression test execution, the testing team can build a test strategy before the beginning of the development phase itself and modify it with every upcoming sprint cycle.
To begin with, Smoke and sanity testing come before regression tests and can save time for testing teams. Sanity testing is a run-through of the basic functionality of an application, prior to the additional testing of a new release, which informally confirms that functionality works as planned.
Steps for creating a Regression testing strategy are as below :
- Finding error-prone areas : In a regression we can prioritize the test cases considering the features related to the new changes/fixes/requirements. Include the test cases that fail most often. Some areas in the application are so error-prone that they can fail after a minor coding modification. You can keep track of these failing test cases during the product cycle and include them in the regression test suite.
- Test case prioritization: Test cases that cover the error-prone areas(those which fail more often) should be included. Sometimes, some functionalities in the application are so error-prone that those will fail even with the slightest modification in the code.
- Analyzing bug reports: Analyze the defect report as with every test execution cycle the automated tool generates a test report that specifies the failed test cases, which step in the test case was affected which in turn affected a particular functionality. Error tracking tools also generate screenshots and failure metrics during regression testing. This helps in identifying and debugging the issue.
- Communication: Testers should communicate with product owners to monitor changes in requirements and assess them. They should communicate with developers to understand which so they know what changes were made during an iteration.
However, the two-level approach is not as simple as it seems. To be successful, this approach requires seamless communication within the project team. Communicating with developers, the testing team will be able to get a comprehensive view of what was done in the iteration and make a well-grounded choice about the necessary type of regression testing.
How to Optimize Regression Testing in Agile?
To streamline regression testing in Agile development, test teams leverage the following methods: combining iteration and full regression testing and automating regression testing for increased velocity required by Agile.
Following this approach, a testing team breaks regression testing into two cycles:
- Iteration regression- The team performs iteration regression at the end of each sprint. Iteration regression specifically focuses on features and changes made in the iteration and areas of the application that could have been affected.
- Full regression- Test engineers run full regression before a release to ensure that the application works as planned.
Why Regression Testing is Difficult for an Agile Team?
1. Regression test growth
The scale of regression testing increases with each sprint, and in large projects regression tests quickly become unmanageable. To ensure regression testing remains manageable, your team should automate, but also review tests frequently and remove obsolete or ineffective tests.
2. Special testing skills
As the project develops, specialist skills will be needed for test areas such as integration and performance testing. The team should leverage test specialists, either within the agile team or from other parts of the organization, to gather and plan testing requirements.
Management and customers sometimes make excessive changes to requirements. These changes can be so volatile that entire iterations are wiped out. This poses a serious risk to any test automation strategy.
4. Cannot use record-and-playback testing tools
Teams need to wait until the functionality is ready to employ traditional, test-last tools with record-and-playback-features. Therefore, traditional automated functional testing tools don’t work in an agile context.
5. Lack of communication
Effective communication should exist between the automation testing team, business analysts, developers, and stakeholders. This ensures a good common understanding of changes to the product, which features are new and require new regression tests, which ones are undergoing changes and should be closely tested, and which ones are removed or deprecated and no longer need regression testing.
6. Test case maintenance
The more test cases you automate, the more you can verify the quality of existing functionality. However, more automated test cases mean more maintenance. If you make your test cases too loosely coupled to product functionality, they may pass even when issues exist. However, if they are too rigid they will need to be rewritten and updated with every small change to the system.
In an agile environment, regression testing plays a very important role to ensure critical functionality is maintained during system modifications. Regression testing acts as a safety net by catching any bugs introduced during the latest feature enhancements or new feature additions and also allows the testing team to focus on key functionality within the current sprint. Also, a well-managed and automated regression test suite gives confidence to the stakeholders and testers for sprint sign-offs.