RequiredByKeys

约 186 字小于 1 分钟

2026-02-11

题目

实现一个通用的RequiredByKeys<T, K>，它接收两个类型参数T和K。

K指定应设为必选的T的属性集。当没有提供K时，它就和普通的Required<T>一样使所有的属性成为必选的。

例如:

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

type UserRequiredName = RequiredByKeys<User, 'name'> // { name: string; age?: number; address?: string }

解题思路

待补充

答案

type RequiredByKeys<T, K> = any

验证

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

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

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

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

type cases = [
  Expect<Equal<RequiredByKeys<User, 'name'>, UserRequiredName>>,
  Expect<Equal<RequiredByKeys<User, 'name' | 'age'>, UserRequiredNameAndAge>>,
  Expect<Equal<RequiredByKeys<User>, Required<User>>>,
  // @ts-expect-error
  Expect<Equal<RequiredByKeys<User, 'name' | 'unknown'>, UserRequiredName>>,
]

参考

无