ExactMatchTypeKeys

ExactMatchTypeKeys<T, U>: { [K in keyof T]-?: [U] extends [T[K]] ? [T[K]] extends [U] ? K : never : never }[keyof T]

Tのプロパティのうち、Uで指定した型と一致するプロパティのキーを取り出す

Example

type Post = {
  title: string
  body: string
  revision?: number
  createdAt: Date
  updatedAt?: Date
}
// Keys => "updatedAt"
type Keys = ExactMatchTypeKeys<Post, Date | undefined>
// Props => { updatedAt?: Date }
type Props = Pick<Post, Keys>

Type parameters

Name
T
U