Integration Testing
Test interactions between multiple components, modules, or services.
When to use me
Use this skill when:
- Components have been unit tested and need to work together
- Testing API contracts between services
- Verifying database interactions work correctly
- Checking third-party service integrations
- Ensuring microservices communicate properly
- Validating data flows through the system
What I do
- Identify integration points between components
- Set up test environments with real or test databases
- Configure service connections and API endpoints
- Test data flow between integrated components
- Verify error handling across component boundaries
- Check contract compliance between services
- Validate end-to-end workflows without UI
Examples
# Run integration tests
npm run test:integration # Node.js integration tests
pytest tests/integration/ # Python integration tests
go test -tags=integration # Go integration tests
# Test specific integrations
npm run test:integration -- --grep "database"
pytest tests/integration/test_api_client.py
# Run with test containers for external services
docker-compose -f docker-compose.test.yml up --abort-on-container-exitOutput format
Integration Test Results:
──────────────────────────────
✅ API Service ↔ Database
✓ User data persists correctly
✓ Transaction rollback on failure
❌ Payment Service ↔ Banking API
✗ Authentication token refresh fails
✗ Currency conversion rate mismatch
⚠️ Email Service ↔ Queue
⚠️ Message retention period too short
Summary: 8 passed, 2 failed, 1 warningNotes
- Integration tests are slower than unit tests
- Use test databases or in-memory databases
- Mock only external third-party services
- Test happy paths and error scenarios
- Clean up test data between tests
- Consider using test containers for external dependencies
- Focus on contract testing for microservices