从节点包扩展类型

Question

如何在不修改 @types 文件的情况下从节点包中扩展类型？

import { Session, useSession } from 'next-auth/client'

// I AM TRYING TO EXTEND THE Session TYPE

export default function Component() {
  // useSession() returns type-> useSession(): [Session, boolean]
  const [session]: [<ENTER EXTENDED TYPE HERE>, boolean] = useSession()
  ...
}

来自@types/next-auth

type Session = SessionBase & GenericObject;

interface SessionBase {
    user: User;
    accessToken?: string;
    expires: string;
}

interface User {
    name?: string | null;
    email?: string | null;
    image?: string | null;
}

结果应该是这样的类型：

type NewSession = NewSessionBase & Session;

interface NewSessionBase {
    user: {
      name?: string | null;
      email?: string | null;
      image?: string | null;
      myCustomData?: {
        uid: string | null;
    }
};
    accessToken?: string;
    expires: string;
}

这将修复错误：“TS2741”，“属性缺少类型但类型需要”

Answer 1

您可以只覆盖Session类型的user属性。

type GenericObject = {}

type Session = SessionBase & GenericObject;

interface SessionBase {
  user: User;
  accessToken?: string;
  expires: string;
}

interface User {
  name?: string | null;
  email?: string | null;
  image?: string | null;
}

type NewSession = NewSessionBase & Session;


type NewUser = {
  name?: string | null;
  email?: string | null;
  image?: string | null;
  myCustomData?: {
    uid: string | null;
  }
}

interface NewSessionBase {
  user: NewUser;
  accessToken?: string;
  expires: string;
}

// The main part of answer
type ExtendedSession = Session & {user: NewUser};

这是用另一种属性替换一种类型的属性的更奇特的方式。 如果您有更复杂的替换逻辑，您可以使用它

type Replace<Obj, Property extends keyof Obj, NewType> = {
  [P in keyof Obj]: P extends Property ? NewType : Obj[P]
}

type Foo = Replace<{ expires: string }, 'expires', number> // { expires: number }