Introduction
Regression testing is one of the most critical testing activities in software development. It ensures that new code changes do not negatively affect existing functionality.
What is Regression Testing?
Regression testing is the process of re-testing previously tested features after code changes, bug fixes, enhancements, or new feature additions.
Its main goal is to ensure system stability and reliability.
Why Regression Testing is Important
- Prevents unexpected failures
- Ensures system stability
- Maintains software quality
- Supports continuous integration and deployment
Types of Regression Testing
- Unit Regression Testing
- Partial Regression Testing
- Complete Regression Testing
- Corrective Regression Testing
- Selective Regression Testing
Regression Testing Process
- Identify impacted areas
- Select relevant test cases
- Prioritize critical scenarios
- Execute regression test suite
- Report defects
- Retest and validate fixes
Real-World Examples
Example 1: E-commerce Website
- New payment gateway added
- Tester verifies cart, checkout, login, and order history
Example 2: Banking Application
- Interest calculation logic updated
- Tester validates account balance and transaction history
Tools Used for Regression Testing
- Selenium
- JUnit
- TestNG
- Jenkins (CI integration)
Advantages of Regression Testing
- Improves product stability
- Reduces production defects
- Builds customer trust
- Supports frequent releases
Regression Testing Interview Questions
What is regression testing?
Regression testing ensures existing functionality works after code changes.
When is regression testing performed?
After bug fixes, enhancements, or new feature additions.
Can regression testing be automated?
Yes, regression testing is commonly automated for efficiency.
Frequently Asked Questions
Is regression testing part of smoke testing?
No. Smoke testing validates build stability, while regression testing validates full system stability after changes.
Who performs regression testing?
QA testers and automation engineers.