Agile regression testing allows development teams to focus on new functionality while maintaining stability with each new product release. Regression testing is used by teams to ensure that the software performs after each modification. Although it is not the most popular type of agile testing, regression testing is vital to ensure agile teams achieve the high velocity they desire.
Regression Testing in an Agile Environment: Basic Concepts
Agile testing requires that each sprint is developed with testing. Testers must ensure that any new changes to the application do not impact existing functionality. This is called regression testing.
Regression testing is used to ensure that the previous functionality of an application still works and that no bugs have been introduced by new changes. Regression testing should be used regardless of whether the software has undergone a minor or major change. Teams should verify that the new code is not in conflict with existing code and that it works as expected.
Agile is characterized by frequent builds and continual changes to the application. Regression testing is essential in agile. Regression testing in agile is only possible if the testing team builds the regression suite at the beginning of product development. They should keep working on it during development sprints.
Methods for Regression Testing
Regression testing can be done in three different ways. Your circumstances, your codebase size, the number and availability of testers, as well as your resources, will determine which approach you choose.
- Retest everything – This involves running all the existing tests on the new codebase. This will only work if the tests are well-designed. This method can be resource-intensive and not feasible for large code bases.
- Selective Re-testing – Sometimes it is possible to identify a subset or set of existing tests that can cover all or nearly all the “moving parts” of your codebase. To find regressions in the codebase, it is enough to run that select set again.
- Prioritized re-testing -used with large codebases. Priority tests are used to address areas that could contain bugs, such as code paths and user actions. After these tests are completed, you can move on to the next tests.
Important Considerations for Automated Regression Testing
Regression testing is a constant process that must be repeated. Regression testing is an essential part of every release cycle to make sure that new developments do not break anything.
Regressions may not always be due to a bug fix or a new feature. Regressions can also occur due to new browser versions, updates to databases, or other changes in the environment. Regression can also indicate a security or performance problem. Manual testers can concentrate on merging complicated cases and testing different environments when there are repeatable and stable regression cases.
When you are creating a strategy to automate regression testing, consider the following:
Automation is suitable for your project size.
Automation is efficient for large-scale and medium-sized projects. This is especially true when testing software that has multiple sub-systems such as web applications or multiuser gaming. Automation may not be worth the cost for a short-term or small project.
Manual testing is a good starting point
Writing automated regression tests against a feature that is still in development can lead to wasted time. Regression testing should be done only after you have passed at least one test manually. Only then can you compare results from the automated and manual tests.
Do not aim for 100% coverage
Regression testing scripts must cover 70-90% manual tests that are repeatable and effective. Test cases that only identify bugs once or report false positives or negatives continuously are not suitable for regression testing. Regression test coverage of 100% is not possible and may lead to lower test results.
Regression Automation Challenges
Your team needs to be aware of any obstacles that could hinder automation efforts.
- Maintenance–automation regression tests suites are not valid indefinitely. It is important to quickly modify a test suite in order to reflect project changes. To identify obsolete test cases, the test team should assess automated regression test suites.
- False Positives – Tests that report failures when there are no problems. This could be due to timing issues, outdated test cases or other objective reasons. This could also be due to poorly designed or poorly coded flaky tests that produce inconsistent results.
What is Regression Testing important in Agile Development?
The team is focused on the functionality that will be delivered during the sprint in an agile framework. While the team may be focusing on a specific product area, they cannot expect to consider the potential risks to the whole system. If the coverage is adequate, a regression test will be used to show the areas that have been affected by recent changes made by the team.
Regression tests should be run as soon as possible after any changes have been made. If feedback is received late, it’s possible that the team has already implemented changes in other parts of the system.
Regression Testing Challenges for Agile Teams
Regression testing can be difficult for agile teams because of common issues:
- Customers and management sometimes make drastic changes to requirements These changes can cause entire iterations to be wiped out. This is a grave risk for any test automation strategy.
- Cannot use record-and-playback testing tools–teams need to wait until functionality is ready to employ traditional, test-last tools with record-and-playback-features. Traditional automated functional testing tools won’t work in an agile environment.
- Regression testing growth–regression tests become more complex with every sprint. Large projects can quickly make it difficult to manage regression tests. Your team should automate but also regularly review and eliminate ineffective or obsolete tests to ensure that regression testing is manageable.
- Lack of communication–effective communication should exist between the automation testing team, business analysts, developers, and stakeholders. This allows for a common understanding of product changes, such as which features have been added and need to be tested in regression, which are under development and should be closely tested. It also helps with deciding which features are being removed or deprecated, and when they will no longer require regression testing.
- Specific testing skills–As the project progresses, specialists will be required for areas like integration and performance testing. To gather and plan testing requirements, the team should draw on test specialists from the agile team as well as other departments.
- Test case maintenance – The more test cases you automate the better you can check quality of existing functionality. More automated test cases means more maintenance. Your test cases should not be too closely tied to the product functionality. They may fail even if there are issues. If they are too rigid, they will need to rewritten and updated for every minor change to the system.
A Regression Testing Strategy for Agile Teams
Before you start a regression testing strategy
- All test cases that you plan to use
- Identify any improvements that could be made to the test case
- Calculate the time it will take to execute the test cases
- Describe what automation is possible and how it can be done.
How to build a regression testing strategy
Smoke and sanity tests
Regression tests can be shortened by smoke and sanity testing. A run-through of the application’s basic functionality before adding testing for a new version. This confirms that the functionality is working as intended.
You will need to conduct smoke testing by using a subset test cases that test the primary and core product workflows. These test cases can be run quickly and can be used for quick results.
To quickly determine if an application is flawed enough to warrant further testing such as regression testing, you can use smoke and sanity testing. This is a better way to run regression tests on an application that doesn’t load, or allows login. Then you can start investigating the reasons why hundreds of thousands of regression test fail.
Identifying error-prone areas
Incorporate the most frequently failing test cases. Some areas of the application are so error-prone they can fail even after minor code modifications. These failing cases can be tracked during the product cycle, and they can be included in the regression test suite.
Test case prioritization
A testing team chooses test cases that are most likely to be affected by project changes. This is called a risk-based approach. They rank them according to their priority. Regression tests are focused on areas that present the highest risk of quality problems.
Prioritize test cases based on critical and often used functionalities. You can reduce the number of regression tests by prioritizing them. This will allow you to save time, make regression runs faster, and do so more often.
Many regression testing tools can integrate with error tracking software. This allows you to view detailed information about the regression test, including what failed, how it failed, and which code line was affected. You can also use error tracking tools to get screenshots and other metrics during regression testing. This will help identify and fix the problem.
To monitor and assess changes in requirements, testers should communicate with product owners. They must communicate with developers in order to understand the requirements and make sure they are aware of any changes made during iterations.
Regression Test Prioritization: A New Approach
Regression test suites can be a burden for agile teams. Regression tests are a key component of large projects. However, teams today are forced to prioritize based on “tribal information” about product areas that are likely to be error-prone, evidence from production faults, as well as imperfect metrics such defect density and code coverage.
Quality Intelligence Platforms, a new category of tools, offer a scientific approach to prioritizing tests. PowerocksMedia, for example, integrates with your regression tools and other tools that you use to test unit, functional, integration, and acceptance. It also collects data about test execution, test coverage, and how often features are actually used in production.
This data gives PowerocksMedia a clear measure of quality risks. It shows you which areas of your product are most susceptible to making errors that could affect your users. You can reduce the number of regression tests you run and increase your sprint velocity by focusing on these areas.