Typed Promise.all

Background

Parallel async operations with Promise.all improve performance, and TypeScript typing ensures correct result handling.

Problem

Write a function that fetches user data and their posts in parallel using Promise.all, returning a typed combined result.

Input

A user ID number to fetch data for.

Output

A combined object with user and posts data, properly typed.

Sample tests

Input: userId=1

Expected: {user: {...}, posts: [...]}

Your solution

Learning objective

Learn typed parallel async operations with Promise.all and tuple destructuring.