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898 - Includes

  • #Type Challenges
  • #TypeScript

질문

JavaScript의 Array.includes 함수를 타입 시스템에서 구현하세요. 타입은 두 인수를 받고, true 또는 false를 반환해야 합니다.

예시:

type isPillarMen = Includes<['Kars', 'Esidisi', 'Wamuu', 'Santana'], 'Dio'> // expected to be `false`

/* _____________ 테스트 케이스 _____________ */
import type { Equal, Expect } from '@type-challenges/utils' type cases = [ Expect<Equal<Includes<['Kars', 'Esidisi', 'Wamuu', 'Santana'], 'Kars'>, true>>, Expect<Equal<Includes<['Kars', 'Esidisi', 'Wamuu', 'Santana'], 'Dio'>, false>>, Expect<Equal<Includes<[1, 2, 3, 5, 6, 7], 7>, true>>, Expect<Equal<Includes<[1, 2, 3, 5, 6, 7], 4>, false>>, Expect<Equal<Includes<[1, 2, 3], 2>, true>>, Expect<Equal<Includes<[1, 2, 3], 1>, true>>, Expect<Equal<Includes<[{}], { a: 'A' }>, false>>, Expect<Equal<Includes<[boolean, 2, 3, 5, 6, 7], false>, false>>, Expect<Equal<Includes<[true, 2, 3, 5, 6, 7], boolean>, false>>, Expect<Equal<Includes<[false, 2, 3, 5, 6, 7], false>, true>>, Expect<Equal<Includes<[{ a: 'A' }], { readonly a: 'A' }>, false>>, Expect<Equal<Includes<[{ readonly a: 'A' }], { a: 'A' }>, false>>, Expect<Equal<Includes<[1], 1 | 2>, false>>, Expect<Equal<Includes<[1 | 2], 1>, false>>, Expect<Equal<Includes<[null], undefined>, false>>, Expect<Equal<Includes<[undefined], null>, false>>, ]

풀이

부록

Equal 구현하기