Testing Strategies

Testing is the backbone of quality engineering. A well-designed testing strategy gives you confidence that your code works correctly, catches regressions before they reach users, and documents how your system is expected to behave. This topic covers the full spectrum of testing — from fast, focused unit tests through comprehensive end-to-end tests — along with accessibility testing in CI pipelines and meaningful coverage metrics.

1. 1
   Unit Testing Fundamentals

   The AAA pattern, test isolation, mocking and stubbing, testing frameworks, and Test-Driven Development basics.
2. 2
   Integration Testing

   Testing how components work together: database tests, API tests, service integration, and test data management.
3. 3
   End-to-End Testing

   Browser-based testing with Playwright and Cypress, the Page Object Model, visual regression testing, and CI integration.
4. 4
   Accessibility Testing in CI

   Integrating Pa11y CI with axe runner into GitHub Actions, interpreting results, and setting failure thresholds.
5. 5
   Test Coverage Metrics

   Line, branch, and function coverage, setting meaningful thresholds, mutation testing, and coverage reporting in CI.