type-challenges-judge

Type Challenges Judge

Problems

Progress

Remove Index Signature

提出詳細

type IsIndexKey<K> =
  K extends string
  ? (string extends K ? true : false)
  : K extends number
  ? (number extends K ? true : false)
  : K extends symbol
  ? (symbol extends K ? true : false)
  : false;

type RemoveIndexSignature<T extends object> = {
  [P in keyof T as IsIndexKey<P> extends true ? never : P]: T[P]
}

提出日時	2025-09-16 03:25:40
問題	Remove Index Signature
ユーザー	balckowl
ステータス	Accepted

テストケース

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

type Foo = {
  [key: string]: any
  foo(): void
}

type Bar = {
  [key: number]: any
  bar(): void
}

type FooBar = {
  [key: symbol]: any
  foobar(): void
}

type Baz = {
  bar(): void
  baz: string
}

type cases = [
  Expect<Equal<RemoveIndexSignature<Foo>, { foo(): void }>>,
  Expect<Equal<RemoveIndexSignature<Bar>, { bar(): void }>>,
  Expect<Equal<RemoveIndexSignature<FooBar>, { foobar(): void }>>,
  Expect<Equal<RemoveIndexSignature<Baz>, { bar(): void; baz: string }>>,
]