---
description: Code style guidelines for Twenty CRM
globs: []
alwaysApply: true
---
# Code Style Guidelines

## Formatting Standards
- **Prettier**: 2-space indentation, single quotes, trailing commas, semicolons
- **Print width**: 80 characters
- **ESLint**: No unused imports, consistent import ordering, prefer const over let

## Naming Conventions
```typescript
// ✅ Variables and functions - camelCase
const userAccountBalance = 1000;
const calculateMonthlyPayment = () => {};

// ✅ Constants - SCREAMING_SNAKE_CASE
const API_ENDPOINTS = {
  USERS: '/api/users',
  ORDERS: '/api/orders',
} as const;

// ✅ Types and Classes - PascalCase
class UserService {}
type UserAccountData = {};
type ButtonProps = {}; // Component props suffix with 'Props'

// ✅ Files and directories - kebab-case
// user-profile.component.tsx
// user-profile.styles.ts
```

## Import Organization
```typescript
// ✅ Correct import order
// 1. External libraries
import React from 'react';
import { useCallback } from 'react';
import styled from 'styled-components';

// 2. Internal modules (absolute paths)
import { Button } from '@/components/ui';
import { UserService } from '@/services';

// 3. Relative imports
import { UserCardProps } from './types';
```

## Function Structure
```typescript
// ✅ Small, focused functions
// ✅ Required parameters first, optional last
const processUserData = (
  user: User,
  options: ProcessingOptions,
  callback?: (result: ProcessedUser) => void
): ProcessedUser => {
  const processedUser = transformUserData(user);
  applyOptions(processedUser, options);
  
  if (callback) {
    callback(processedUser);
  }
  
  return processedUser;
};
```

## Comments
```typescript
// ✅ Use short-form comments, NOT JSDoc blocks
// ✅ Explain business logic and non-obvious intentions
// Apply 15% discount for premium users with orders > $100
const discount = isPremiumUser && orderTotal > 100 ? 0.15 : 0;

// TODO: Replace with proper authentication service
const isAuthenticated = localStorage.getItem('token') !== null;

// ✅ Multi-line comments use multiple // lines (NOT /** */ blocks)
// Calculates the total price after applying tax and discount
// Returns the final price that should be charged to the customer
const calculateTotalPrice = (basePrice: number): number => {
  // Implementation
};

// ❌ AVOID JSDoc blocks - use short comments instead
/**
 * This style is NOT preferred in this codebase
 */
```

## Security Patterns
```typescript
// ✅ CSV Export: Always apply security first, then formatting
const safeValue = formatValueForCSV(sanitizeValueForCSVExport(userInput));

// ✅ Input validation before processing
const sanitizedInput = validateAndSanitize(userInput);
const result = processData(sanitizedInput);
```

## Error Handling
```typescript
// ✅ Proper error types and meaningful messages
try {
  const user = await userService.findById(userId);
  if (!user) {
    throw new UserNotFoundError(`User with ID ${userId} not found`);
  }
  return user;
} catch (error) {
  logger.error('Failed to fetch user', { userId, error });
  throw error;
}
```