type DeepPartial<T> = T extends object ? {
    [P in keyof T]?: DeepPartial<T[P]>;
} : T;

interface User {
    id: string;
    name: string;
    address: {
        street: string;
        city: string;
        zip: number;
    };
    preferences?: {
        theme: 'dark' | 'light';
        notifications: boolean;
    };
}

type PartialUserUpdate = DeepPartial<User>;

const update1: PartialUserUpdate = {
    name: 'Jane Doe',
    address: {
        city: 'New York'
    }
};

const update2: PartialUserUpdate = {
    preferences: {
        theme: 'dark'
    }
};

// Example of DeepPartial with an array - optional, but good to cover
type DeepPartialArray<T> = T extends Array<infer U> ? Array<DeepPartial<U>> : DeepPartial<T>;

interface Post {
    id: number;
    title: string;
    comments: { author: string; text: string }[];
}

type PartialPostUpdate = DeepPartialArray<Post>;

const postUpdate: PartialPostUpdate = {
    comments: [{ author: 'Alice' }] // Notice how it makes array elements DeepPartial, not just the array itself optional
};