👉
Date: April 14, 2026 Author: TypeScript Team / Community Spotlight ts playground 35
let data: DeepReadonly<ApiResponse>; data.user.settings.theme = "dark"; // Error: Cannot assign to 'theme' 👉 Date: April 14, 2026 Author: TypeScript Team
type DeepReadonly<T> = { readonly [P in keyof T]: DeepReadonly<T[P]>; }; interface ApiResponse { user: { name: string; settings: { theme: string } }; } 👉 Date: April 14