Which concept involves re-running existing tests to ensure changes have not introduced new defects?

Which concept involves re-running existing tests to ensure changes have not introduced new defects?

• A. Regression Testing
• B. Unit Testing
• C. Integration Testing
• D. Smoke Testing

Answer: (A)

The concept being tested is re-running existing tests to verify that changes haven’t introduced new defects, which is known as regression testing. After making changes—whether bug fixes, feature tweaks, or refactoring—you run the same suite of tests you’ve already created to ensure that previously working functionality still behaves correctly. This helps catch unintended side effects that new code can cause, providing confidence that the system remains stable. Unit testing focuses on verifying individual components or functions in isolation. Integration testing checks how different modules work together. Smoke testing is a quick check to see if the most critical functions operate at a high level, just to confirm the build is usable. In contrast, regression testing specifically targets ensuring that existing, established behavior remains intact after changes, by re-running the broader set of existing tests.

The concept being tested is re-running existing tests to verify that changes haven’t introduced new defects, which is known as regression testing. After making changes—whether bug fixes, feature tweaks, or refactoring—you run the same suite of tests you’ve already created to ensure that previously working functionality still behaves correctly. This helps catch unintended side effects that new code can cause, providing confidence that the system remains stable.

Unit testing focuses on verifying individual components or functions in isolation. Integration testing checks how different modules work together. Smoke testing is a quick check to see if the most critical functions operate at a high level, just to confirm the build is usable. In contrast, regression testing specifically targets ensuring that existing, established behavior remains intact after changes, by re-running the broader set of existing tests.