Coding Standards¶

Detailed coding standards are in the .rules/ directory.

Quick Reference¶

TypeScript¶

Strict mode enabled
No any types
Explicit return types on exported functions

// Good
export function calculateTotal(items: Item[]): number {
  return items.reduce((sum, item) => sum + item.price, 0);
}

// Bad - implicit return type, uses any
export function calculateTotal(items: any) {
  return items.reduce((sum, item) => sum + item.price, 0);
}

Naming Conventions¶

Type	Convention	Example
Functions	camelCase	`getUserById`
Variables	camelCase	`totalPrice`
Types/Interfaces	PascalCase	`UserProfile`
Constants	SCREAMING_SNAKE	`MAX_RETRIES`
Files	kebab-case	`user-profile.ts`

React Components¶

Server Components by default
'use client' only when needed
Feature folders in src/features/

// Server Component (default)
export default function UserProfile({ userId }: { userId: string }) {
  // Can use async/await directly
  const user = await getUser(userId);
  return <div>{user.name}</div>;
}

// Client Component (when needed)
'use client';
export function Counter() {
  const [count, setCount] = useState(0);
  return <button onClick={() => setCount(c => c + 1)}>{count}</button>;
}

API Routes¶

Use Result types, not thrown errors:

type ApiResult<T> =
  | { success: true; data: T }
  | { success: false; error: string; code?: string };

Example:

export async function GET(req: NextRequest): Promise<Response> {
  const session = await getServerSession(authOptions);

  if (!session) {
    return Response.json(
      { success: false, error: 'Unauthorized', code: 'AUTH_REQUIRED' },
      { status: 401 }
    );
  }

  const data = await fetchData();
  return Response.json({ success: true, data });
}

Error Codes¶

const ERROR_CODES = {
  AUTH_REQUIRED: 'Authentication required',
  AUTH_EXPIRED: 'Session expired',
  FORBIDDEN: 'Not authorized for this action',
  VALIDATION_ERROR: 'Invalid input data',
  NOT_FOUND: 'Resource not found',
} as const;

Full Standards¶

Standard	File
TypeScript	.rules/typescript.md
React	.rules/react.md
API Routes	.rules/api.md
Security	.rules/security.md
Performance	.rules/performance.md
Git	.rules/git.md
Testing	.rules/testing.md
AI/LLM	.rules/ai-llm.md