TS - Extract<T, U>

개념
한마디로, T에서 U타입 중 할당 가능한 것만 리턴
정리하지면, pick은 prop을, extract는 type을...

type Extract<T, U> = T extends U ? T : never

 

Examples

type Company = {
  id: string
  name: string
}

type Product = {
  price: number
  rating: number
}

type fakeProduct = Extract<Company | Product, Company>
// type fakeProduct = {
//    id: string;
//    name: string;
// }

 

참고
https://velog.io/@ggong/Typescript의-유틸리티-타입-1-Record-Extract-Pick