type-challenges-judge

Type Challenges Judge

Problems

Progress

String Join

提出詳細

type JoinerImpl<T extends readonly unknown[], D extends string> =
    T extends [infer T1 extends string, ...infer T2]
    ? T2 extends []
      ? T1
      : `${T1}${D}${JoinerImpl<T2,D>}`
    : ""
type Joiner<D extends string> =
  <T extends string[]>(...args: T) => JoinerImpl<T,D>
declare function join<D extends string>(delimiter: D): Joiner<D>

提出日時	2023-09-20 01:45:58
問題	String Join
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'

// Edge cases
const noCharsOutput = join('-')()
const oneCharOutput = join('-')('a')
const noDelimiterOutput = join('')('a', 'b', 'c')

// Regular cases
const hyphenOutput = join('-')('a', 'b', 'c')
const hashOutput = join('#')('a', 'b', 'c')
const twoCharOutput = join('-')('a', 'b')
const longOutput = join('-')('a', 'b', 'c', 'd', 'e', 'f', 'g', 'h')

type cases = [
  Expect<Equal<typeof noCharsOutput, ''>>,
  Expect<Equal<typeof oneCharOutput, 'a'>>,
  Expect<Equal<typeof noDelimiterOutput, 'abc'>>,
  Expect<Equal<typeof twoCharOutput, 'a-b'>>,
  Expect<Equal<typeof hyphenOutput, 'a-b-c'>>,
  Expect<Equal<typeof hashOutput, 'a#b#c'>>,
  Expect<Equal<typeof longOutput, 'a-b-c-d-e-f-g-h'>>,
]