Regression testing is a type of software testing that focuses on verifying that modifications or enhancements made to a software application do not unintentionally introduce new defects or cause existing functionality to break. It involves retesting previously tested functionality to ensure its continued proper functioning after changes have been made to the software.
The primary goal of regression testing is to uncover regressions, which are defects that occur when changes to the software code or configuration adversely affect previously functioning features. Regression testing helps ensure that the software remains stable and reliable throughout the development or maintenance process.
Regression testing typically follows one of the following approaches:
- Selective Regression Testing: In this approach, specific test cases or test suites are selected based on their relevance to the changes made in the software. The focus is on testing the areas that are most likely to be affected by the modifications.
- Full Regression Testing: This approach involves retesting the entire software application or a significant portion of it to ensure that all functionalities are working correctly. It provides a higher level of confidence but can be time-consuming and resource-intensive.
Regression testing can be performed at various stages of the software development life cycle, including:
- During Maintenance: When bug fixes or enhancements are made to a software application, regression testing ensures that the changes do not introduce new issues or break existing functionality.
- After System Upgrades: When the software undergoes updates or upgrades, regression testing is performed to verify that the system as a whole is still functioning correctly.
- When Configurations Change: If there are changes in the software’s configuration, such as the underlying hardware or software platforms, regression testing ensures that the software remains compatible and functions as expected.
Regression testing is typically automated to efficiently re-execute test cases and compare the results with previously established baselines. Automated regression testing allows for frequent and thorough testing, reducing the effort and time required for testing while ensuring effective coverage.
By performing regression testing, software teams can identify and address issues early, prevent the introduction of new defects, and maintain the overall quality and stability of the software application throughout its lifecycle.