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PartialByKeys

提出詳細

type Merge<F,S,X=Omit<F,keyof S> & S> = {
  [ K in keyof X ]: X[K]
}
type PartialKeyOnly<T,Key> = {
  [ K in keyof T as K extends Key ? K : never]?: T[K]
}
type PartialByKeys<T,Key=keyof T> =
  Merge<T,PartialKeyOnly<T,Key>>

提出日時	2023-09-15 13:34:09
問題	PartialByKeys
ユーザー	sankantsu
ステータス	Accepted

テストケース

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

interface User {
  name: string
  age: number
  address: string
}

interface UserPartialName {
  name?: string
  age: number
  address: string
}

interface UserPartialNameAndAge {
  name?: string
  age?: number
  address: string
}

type cases = [
  Expect<Equal<PartialByKeys<User, 'name'>, UserPartialName>>,
  Expect<Equal<PartialByKeys<User, 'name' | 'unknown'>, UserPartialName>>,
  Expect<Equal<PartialByKeys<User, 'name' | 'age'>, UserPartialNameAndAge>>,
  Expect<Equal<PartialByKeys<User>, Partial<User>>>,
]