TypeScript 強制轉換為 Partial<T> 但密鑰必須存在

Question

我需要兩種實用程序類型：一種類型的子集具有匹配的值類型，另一種只需要鍵存在於另一種類型中。
我想出了以下乍一看似乎沒問題的方法，但我不禁想知道我是否正在做一些已經內置於 TS (v4.7) 中的東西。

更新：
我研究這個的問題不在於類型本身，而在於鑄造。 將{ nammme: 'John' as any } as Partial<Person>有效，我想阻止。 我需要覆蓋某些屬性的類型（但最好不是全部）。

// This works...
const fields: Partial<DbUser> = {
  organizationId: FieldValue.delete() as any,
  groups: FieldValue.delete() as any,
};

return getFirestore()
  .collection(constants.dbCollections.users)
  .doc(context.auth.uid)
  .update(fields);

// This allows typos...
return getFirestore()
  .collection(constants.dbCollections.users)
  .doc(context.auth.uid)
  .update({
    organizationId: FieldValue.delete() as any,
    groups: FieldValue.delete() as any,
    typoooo: 1 as any,
} as Partial<DbUser>);

代碼示例

type Person = {
  name: string;
  age: number;
};

export type KeysIn<T> = {
  [key in keyof Partial<T>]: any;
};

export type MustContainKeyButTypeOfKeyCanBeOverwritten<T> = unknown; // ?

// Valid: Key exists in Person
const valid1: KeysIn<Person> = {
  name: 0,
};

// Valid: Key exists in Person and type matches
const valid2: Partial<Person> = {
  name: '',
};

// Invalid: Key does not exist in Person
const invalid1: KeysIn<Person> = {
  x: true,
};

// Invalid: Key exists in Person but type does not match
const invalid2: Partial<Person> = {
  name: 0,
};

// Invalid: Key does not exist in Person
const invalid3: Partial<Person> = {
  x: true,
};

// Typo with cast to any
const invalid4: KeysIn<Person> = {
  namessss: '' as any,
};

const invalid5 = {
  namessss: '' as any,
} as Partial<Person>; // Why is this valid?

const invalid6 = {
  namessss: '' as any,
} as KeysIn<Person>; // Why is this valid? I need this to be invalid

const idealExample: MustContainKeyButTypeOfKeyCanBeOverwritten<Person> = {
  name: 1 as any, // Allowed type override
  aggggggge: 1, // Typo, invalid
  age: '2', // Wrong type, invalid
};

我可以在防止拼寫錯誤的同時只用新類型覆蓋某些鍵嗎？

^{堆棧閃電戰}

Answer 1

Partial做你想要的Subset 。

export type Subset<T> = Partial<T>;

對於KeysIn ，我認為您的定義是有道理的，以下是另一種選擇。

export type KeysIn<T> = Partial<Record<keyof T, any>>;