Regression testing and retesting are important practices in software engineering that help ensure the quality and reliability of software applications. They are both types of software testing, but they serve different purposes and are performed at different stages of the software development lifecycle.
Regression Testing:
- Purpose: Regression testing is conducted to ensure that recent changes or updates to the software (such as code modifications, bug fixes, new features, or enhancements) do not introduce new defects or break existing functionality.
- Scope: It involves re-running a comprehensive set of test cases that cover various aspects of the software's functionality.
- Frequency: Regression testing is typically performed frequently, often as part of a continuous integration (CI) or continuous delivery (CD) pipeline. It's done whenever there are code changes.
- Automation: Many regression tests are automated to speed up the process and ensure consistent and repeatable results.
- Test Cases: The test cases for regression testing include both new and existing test cases to verify that everything still works as expected.
Retesting:
- Purpose: Retesting focuses on verifying that a specific defect or issue reported in a previous testing cycle has been fixed correctly. It ensures that the reported problem no longer exists in the updated version of the software.
- Scope: It involves executing the same test case that initially exposed the defect.
- Frequency: Retesting is typically performed on an as-needed basis when defects are reported and subsequently fixed.
- Automation: While some aspects of retesting may be automated, the primary focus is on manually verifying that the specific issue has been resolved.
- Test Cases: The test cases for retesting are typically limited to those that are directly related to the reported defect.
Here's a typical workflow that incorporates both regression testing and retesting:
- A defect or issue is reported by a tester or user.
- The development team investigates the issue and makes the necessary code changes to fix it.
- After fixing the issue, the software undergoes retesting to verify that the reported problem is resolved.
- Once retesting confirms that the issue is fixed, the software is subjected to regression testing to ensure that the fix did not introduce new defects or break existing functionality.
- If the regression testing uncovers any new issues, they are addressed, and the cycle continues until no new problems are found.
- The software is then considered ready for release or deployment.
In summary, regression testing and retesting are complementary testing practices in software engineering. Regression testing helps maintain overall software quality by ensuring that new changes do not break existing functionality, while retesting focuses specifically on verifying the resolution of reported defects. Both practices contribute to delivering reliable and high-quality software to end-users.
