Item 67: Export All Types That Appear in Public APIs

要点

• Export types that appear in any form in any public method. Your users will be able to extract them anyway, so you may as well make it easy for them.
• 导出在任何公共方法中以任何形式出现的类型。你的用户反正能够提取它们，所以不如直接让他们更容易获取。

正文

interface SecretName {
  first: string
  last: string
}

interface SecretSanta {
  name: SecretName
  gift: string
}

export function getGift(name: SecretName, gift: string): SecretSanta {
  // ...
}

💻 playground

---

type MySanta = ReturnType<typeof getGift>
//   ^? type MySanta = SecretSanta
type MyName = Parameters<typeof getGift>[0]
//   ^? type MyName = SecretName

💻 playground