TypeScript DeepReadonly generic type.

DeepReadonly.ts

type DeepReadonly<T> =
	T extends (infer R)[] ? DeepReadonlyArray<R> :
	T extends Function ? T :
	T extends object ? DeepReadonlyObject<T> :
	T;

interface DeepReadonlyArray<T> extends ReadonlyArray<DeepReadonly<T>> { }

type DeepReadonlyObject<T> = {
	readonly [P in keyof T]: DeepReadonly<T[P]>;
};

export default DeepReadonly;