What is Regression Testing and when should it be performed?

Regression Testing is the process of retesting a software application after changes (bug fixes, enhancements, or new features) to ensure that existing functionality still works correctly and no new defects have been introduced.

When to Perform Regression Testing

• After Bug Fixes: Verify the fix doesn’t break other features
• New Feature Addition: Ensure new code doesn’t impact existing functionality
• Code Refactoring: Validate that optimization doesn’t introduce bugs
• Environment Changes: After infrastructure or configuration updates
• Before Release: Final validation before production deployment
• Integration: When integrating with third-party systems

Types of Regression Testing

1. Complete Regression: Re-execute all test cases
2. Partial Regression: Test only affected modules
3. Unit Regression: Test at code/unit level
4. Regional Regression: Test specific region/module

Best Practices

• Automate regression test suites for efficiency
• Prioritize test cases based on risk and impact
• Maintain a regression test suite that’s regularly updated
• Use version control for test scripts