type-challenges-judge

Type Challenges Judge

Problems

Progress

Ranking

Readonly 2

提出詳細

type MyReadonly2<T, K extends keyof T = any> =
  { readonly [U in keyof T as U extends K ? U : never]: T[U] } &  // ① K に該当するプロパティだけを抽出 し readonly にする
  { [U in keyof T as U extends K ? never : U]: T[U] }  // ② K に該当しないプロパティだけを抽出

提出日時	2023-08-31 14:12:37
問題	Readonly 2
ユーザー	snaka
ステータス	Accepted

テストケース

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

type cases = [
  Expect<Alike<MyReadonly2<Todo1>, Readonly<Todo1>>>,
  Expect<Alike<MyReadonly2<Todo1, 'title' | 'description'>, Expected>>,
  Expect<Alike<MyReadonly2<Todo2, 'title' | 'description'>, Expected>>,
]

interface Todo1 {
  title: string
  description?: string
  completed: boolean
}

interface Todo2 {
  readonly title: string
  description?: string
  completed: boolean
}

interface Expected {
  readonly title: string
  readonly description?: string
  completed: boolean
}