Pick-TS

A best-effort typesafe(er¹) function to pick selected object fields.

import pick from "pick-ts"
 
const person = {
  name: "John",
  age: 20
}
 
type Named = {
  name: string
}
 
// These lines works
const n: Named = pick("name")(person)
const p: Person = pick("name", "age")(person)
 
// But this will fail at compilation time
const t = pick("title")(person)
const z: Named = pick("title")({ title: "Aloha" })

Limitations

1. As picked type is infered from pick argument value types - setting explicit keys type will break result type:

type Person = {
  name: string
  age: number
}
 
// This will compile, but doesn't work as expected!
const p: Person = pick<keyof Person>()({ name: "John", age: 20 })

Related Links

• https://github.com/Microsoft/TypeScript/issues/13298

Contribute

Perfection is Achieved Not When There Is Nothing More to Add, But When There Is Nothing Left to Take Away

Fork, Contribute, Push, Create pull request, Thanks.