#31968 - PathValue

questions/31968-medium-pathvalue/README.md

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+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:
+
+```typescript
+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'
+```

questions/31968-medium-pathvalue/info.yml

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+difficulty: medium
+title: PathValue
+tags: object, inference, generic, recursive, conditional
+author:
+ github: jw-r
+ name: 류정우
+

questions/31968-medium-pathvalue/template.ts

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

questions/31968-medium-pathvalue/test-cases.ts

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+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;