Regression testing is a type of software testing that focuses on verifying that existing functionality still works as intended after code changes. These changes can include:

  • Bug fixes
  • New features
  • Code refactoring
  • Performance improvements
  • Dependency updates The goal is to ensure that nothing that previously worked has been broken as a result of modifications.

Why Is It Important?

When you make a change to a software system, even a small one, it can have unintended side effects. Regression testing mitigates the risk of such issues by retesting previously tested components.

Key Characteristics

  • Broad scope: Covers both affected and potentially unaffected areas.
  • Repetitive: Often run repeatedly after each major change.
  • Automated: Ideally part of the CD pipeline for speed and consistency.
  • Risk-based: High-risk or business-critical areas often get prioritized.

Best Practices

  • Automate frequently-run tests.
  • Prioritize critical functionality and high-risk areas.
  • Maintain a clean, updated test suite.
  • Use version control to track test changes.
  • Integrate with CI/CD pipelines.
  • Monitor test coverage.