StockFlow - Cursor IDE Rules

# StockFlow - Cursor IDE Rules

## Project Context
This is a MERN stack inventory management application with:
- Backend: Node.js + Express + MongoDB
- Frontend: React + TailwindCSS
- Auth: JWT-based authentication

## Code Style

### JavaScript/Node.js
- Use ES6+ features (const/let, arrow functions, async/await)
- Use async/await instead of callbacks or .then()
- Use destructuring for object and array access
- Prefer template literals for string concatenation

### React
- Use functional components with hooks
- Use named exports for components
- Keep components small and focused
- Use the api service layer for all API calls

### Naming Conventions
- Components: PascalCase (ProductCard.js)
- Functions: camelCase (handleSubmit)
- Constants: UPPER_SNAKE_CASE
- Files: camelCase for JS, PascalCase for React components

## File Patterns

### Backend Controller Pattern
```javascript
const getSomething = async (req, res) => {
    try {
        const data = await Model.find();
        res.json(data);
    } catch (error) {
        res.status(500).json({ message: error.message });
    }
};
```

### Frontend API Call Pattern
```javascript
import { somethingAPI } from '../services/api';

const fetchData = async () => {
    try {
        const response = await somethingAPI.getAll();
        setData(response.data);
    } catch (error) {
        console.error('Error:', error);
    }
};
```

## Important Notes

- MongoDB uses `_id` not `id` - always use `_id` in frontend
- All protected routes need Bearer token in Authorization header
- User roles: Admin > Manager > Staff
- Validation is done in middleware/validate.js
- Environment variables in backend/.env

## Do NOT
- Hardcode credentials or secrets
- Skip input validation
- Use callbacks instead of async/await
- Create components without proper error handling
- Ignore TypeScript/ESLint warnings

## Testing
- Backend tests use Jest + mongodb-memory-server
- Frontend tests use React Testing Library
- Run `npm test` in respective directories

## Common Commands
```bash
# Start backend (from /backend)
npm run dev

# Start frontend (from /frontend)
npm start

# Run backend tests
npm test
```