# Cursor Rules for [Nom du Projet]

## General Guidelines

You are an expert TypeScript/Node.js developer working on a backend API project.

Always:
- Write clean, maintainable, well-documented code
- Follow the project's coding conventions
- Include error handling for all operations
- Write comprehensive tests for new features
- Consider security implications of every change

Never:
- Hardcode secrets or API keys
- Skip input validation
- Ignore TypeScript errors
- Commit code without tests

## Code Style

- Use TypeScript strict mode
- Prefer async/await over callbacks
- Use descriptive variable names (no single letters except loops)
- Maximum line length: 100 characters
- Indentation: 2 spaces

## Testing

- Write tests before or alongside implementation (TDD encouraged)
- Test coverage minimum: 80%
- Use Jest for unit tests, Playwright for E2E
- Mock external dependencies in unit tests

## Security

- Always validate and sanitize user inputs
- Use parameterized queries for database operations
- Implement rate limiting on public endpoints
- Never log sensitive information

## Commit Messages

Follow Conventional Commits format:
```
type(scope): short description

Detailed explanation if needed.

---
🤖 AI-Assisted Development
Tool: Cursor (claude-sonnet-4-5)
Agent: [Suggestion|Guided|Autonomous]
Human validation: [What was reviewed]
```

Types: feat, fix, docs, style, refactor, test, chore

## Documentation

- Add JSDoc comments for all public functions
- Update README.md when adding major features
- Document breaking changes in CHANGELOG.md

## File Organization

When creating new files:
- Place API routes in /src/api
- Place business logic in /src/services
- Place data models in /src/models
- Place utilities in /src/utils

## Dependencies

Before adding a dependency:
1. Check if functionality can be implemented without it
2. Verify package is well-maintained (recent updates)
3. Check for known vulnerabilities
4. Document why it's needed

## Error Handling

All async operations must have proper error handling:
```typescript
try {
  await riskyOperation();
} catch (error) {
  logger.error('Operation failed', { error, context });
  throw new AppError('User-friendly message', 500);
}
```

## Database Queries

- Always use parameterized queries
- Implement pagination for list endpoints
- Add database indexes for frequent queries
- Use transactions for multi-step operations