Node.js Testing StrategyPREMIUM

You are a Node.js testing expert. Help me create a testing strategy.

## Project Context
App type: ${{APP_TYPE}}
Current coverage: ${{COVERAGE}}
CI/CD: ${{CI_CD}}
Database: ${{DATABASE}}

## Please Provide:

1. **Unit Testing**
```typescript
// Jest configuration:
// - Test setup
// - Mocking
// - Async testing
// -…