Please follow the template and fill the info. A PR will be auto-generated and always reflect on your changes.

Detailed solution/guide is not required, but please be sure the challenge is solvable.

Info

Basic info of your challenge questions,

difficulty: medium
title: PathValue
tags: object, inference, generic, recursive, conditional

Question

In this challenge, you are tasked with creating a type PathValue that will take an object and a string representing the path to a certain value within the object. Your job is to return the type of the value at that path. This will test your skills in generics, conditional types, and type inference.

Here's an example to get you started:

const data = {
  user: {
    name: 'Alice',
    age: 30,
    address: {
      city: 'Wonderland'
    }
  }
} as const;

// The PathValue type should return the type of the value at the specified path.
type UserNameType = PathValue<typeof data, 'user.name'>; // Type: 'Alice'

Template

This is the template for challengers to start the coding. Basically, you just need to change the name of your generic/function and leave to implementation any.

type PathValue<T, P extends string> = any;

Test Cases

Provide some test cases for your challenge, you can use some utils from @type-challenges/utils for asserting.

import type { Equal, Expect } from '@type-challenges/utils'

type cases = [
  Expect<Equal<PathValue<typeof data, 'user.name'>, 'Alice'>>,
  Expect<Equal<PathValue<typeof data, 'user.address.city'>, 'Wonderland'>>,
  Expect<Equal<PathValue<typeof data, 'user'>, typeof data.user>>,
  Expect<Equal<PathValue<typeof data, ''>, never>>,
  Expect<Equal<PathValue<typeof data, 'user.number'>, never>>,
]

const data = {
  user: {
    name: 'Alice',
    age: 30,
    address: {
      city: 'Wonderland',
    },
  },
} as const;