Regression testing is a type of software testing that ensures previously developed and tested software still performs correctly after it was changed. Changes may include software enhancements, patches, configuration changes, bugfixes, dependency updates or others.
The primary goal of regression testing is to identify bugs that could have been introduced into previously tested code by these new modifications.
Why is it Important to do Regression Testing?
Regression testing is crucial because it catches bugs and errors that could severely impact the user experience or software functionality after an update. Without regression testing, an update could inadvertently break features that were working perfectly before. This in turn would lead to a poor user experience and potentially costly fixes in terms of time and resources.
Regression Testing Example in Practice
Imagine a banking application that introduces a new feature to display monthly expenditure. A regression test would involve not only testing this new feature but also checking that existing functionalities, such as fund transfers, account balance checks, loan applications and other functionality still work as expected.
Tools and Frameworks
Several tools and frameworks facilitate regression testing, making it more efficient and less time-consuming. Some of the most popular ones are:
- Selenium: A powerful tool for automating web browsers, Selenium is ideal for regression testing web applications.
- Appium: Similar to Selenium but for mobile applications. Appium supports iOS and Android app testing.
- Cypress: A modern web testing framework that runs in the browser, making it fast and easy to use for web application testing.
- QTP/UFT: A widely used tool for functional and regression testing, offering robust features for test automation.
Regression Testing Techniques
- Retest All: This involves testing the whole application after each change, which can be time-consuming.
- Test Selection: Only tests that are affected by the recent changes are re-executed, this is a faster option.
- Test Case Prioritization: Tests are ranked based on their importance. Higher-priority tests are executed first.
The Difference Between Regression Testing and Retesting
Regression Testing checks for unintended side effects after updates in software components.
Retesting is focused on verifying that specific bugs have been fixed in the new code.
Defining a Regression Test Case
A good regression test case should be:
- Automatable: Suitable for automation, to save time and effort in future testing cycles.
- Relevant: Directly related to the recent changes or the application areas most likely to be affected by them.
- Reusable: Able to be used in future regression cycles.
- Repeatable: Should yield consistent results every time it is executed, to avoid flaky test results.
Best Practices in Regression Testing
- Automate Where Possible: Automated regression testing saves time and effort, especially for large projects.
- Keep Tests Updated: As the software evolves, so should the regression tests to remain relevant.
- Focus on Key Functionalities: Prioritize testing on the application's core functionalities that users interact with the most.
- Regularly Review Test Cases: Eliminate obsolete tests and update existing ones as needed.
TestingBot provides various Visual Regression Testing options to quickly and easily run regression tests against your website or app.
