testing

# Testing Skills ## Overview Comprehensive testing knowledge for building reliable, maintainable software with confidence in deployments. ## Categories ### Fundamentals - Testing Pyramid - Test-Driven Development (TDD) - Behavior-Driven Development (BDD) - Core Testing Principles ### Unit Testing - Test isolation and independence - Mocking and stubbing strategies - Test doubles (mocks, stubs, spies, fakes) - Effective assertions ### Integration Testing - Database integration tests - API endpoint testing - External service testing - Container-based testing ### End-to-End Testing - Browser automation - Mobile app testing - Visual regression testing - Cross-browser testing ### Test Patterns - Arrange-Act-Assert (AAA) - Given-When-Then - Test fixtures and factories - Page Object Model ### Advanced Testing - Property-based testing - Mutation testing - Contract testing - Chaos engineering ## Test Pyramid ``` ╱╲ ╱ ╲ E2E Tests ╱────╲ (Few, Slow, Expensive) ╱ ╲ ╱────────╲ Integration Tests ╱ ╲ (Medium) ╱────────────╲ ╱ ╲ Unit Tests ╱________________╲ (Many, Fast, Cheap) ``` ## Quick Reference | Test Type | Speed | Scope | Confidence | Cost | |-----------|-------|-------|------------|------| | Unit | Fast (ms) | Single unit | Low-Medium | Low | | Integration | Medium (s) | Multiple units | Medium-High | Medium | | E2E | Slow (min) | Full system | High | High | ## When to Use Each Type ### Unit Tests - Business logic validation - Algorithm correctness - Edge case handling - Pure functions ### Integration Tests - Database operations - API endpoints - Service interactions - Message queues ### E2E Tests - Critical user journeys - Payment flows - Authentication - Cross-service workflows ## Directory Structure ``` skills/testing/ ├── _index.md ├── fundamentals/ │ ├── testing-pyramid.md │ ├── test-driven-development.md │ ├── behavior-driven-development.md │ └── testing-principles.md ├── unit-testing/ │ ├── unit-test-basics.md │ ├── mocking-strategies.md │ ├── test-doubles.md │ └── assertion-patterns.md ├── integration-testing/ │ ├── integration-test-basics.md │ ├── database-testing.md │ ├── api-testing.md │ └── external-service-testing.md ├── e2e-testing/ │ ├── e2e-basics.md │ ├── browser-testing.md │ ├── mobile-testing.md │ └── visual-regression.md ├── patterns/ │ ├── arrange-act-assert.md │ ├── given-when-then.md │ ├── test-fixtures.md │ ├── factory-patterns.md │ └── page-object-model.md ├── advanced/ │ ├── property-based-testing.md │ ├── mutation-testing.md │ ├── contract-testing.md │ └── chaos-testing.md └── ci-cd/ ├── test-automation.md ├── coverage-reporting.md └── flaky-tests.md ``` ## Related Skills - [Code Quality](../code-quality/_index.md) - [CI/CD](../ci-cd/_index.md) - [Security](../security/_index.md)