regression-io/claude-config-plugins/style

// Prefer interfaces for objects
interface User {
  id: number;
  name: string;
  email: string;
  roles?: string[];
}
// Use types for unions, intersections, primitives
type Status = 'active' | 'inactive' | 'pending';
type ID = string | number;
// Generics
function first<T>(items: T[]): T | undefined {
  return items[0];
}

{
  "compilerOptions": {
    "strict": true,
    "noImplicitAny": true,
    "strictNullChecks": true,
    "noUnusedLocals": true,
    "noUnusedParameters": true
  }
}

// ❌ Bad
function process(data: any): any { ... }
// ✅ Good
function process<T extends Record<string, unknown>>(data: T): ProcessedData { ... }
// Use unknown for truly unknown types
function parseJSON(text: string): unknown {
  return JSON.parse(text);
}

// Optional chaining
const name = user?.profile?.name;
// Nullish coalescing
const displayName = name ?? 'Anonymous';
// Type guards
function isUser(obj: unknown): obj is User {
  return typeof obj === 'object' && obj !== null && 'id' in obj;
}

// Named imports (preferred)
import { User, UserService } from './user';
// Type-only imports
import type { Config } from './config';
// Avoid default exports (harder to refactor)
export { UserService };  // Named export preferred