因此，您需要推断键但限制值类型的东西，并使用多余的属性检查来禁止额外的属性。我认为获得这种行为的最简单方法是引入一个helper函数：

// Let's give a name to this type
interface ElementType {
  nodes: number,
  symmetric?: boolean
}

// helper function which infers keys and restricts values to ElementType
const asElementTypes = <T>(et: { [K in keyof T]: ElementType }) => et;

这个辅助函数从et的Map类型推断T的类型。现在你可以这样使用它：

const elementsTyped = asElementTypes({
  square: { nodes: 4, symmetric: true },
  triangle: { nodes: 3 },
  line: { nodes: 2, notSymmetric: false /* error where you want it */} 
});

结果elementsTyped的类型（一旦修复错误）将具有推断的键square、triangle和line，值为ElementType。
希望对你有用。祝你好运！

TypeScript >=4.9.0

TypeScript 4.9.0添加了satisfies关键字，可用于在推断键时约束对象的值。

type ElementValue = {
  nodes: number;
  symmetric?: boolean;
};

const elements = {
  square: { nodes: 4, symmetric: true },
  triangle: { nodes: 3 },
} satisfies Record<string, ElementValue>;

type Elements = typeof elements;
type ElementType = keyof Elements;

function isSymmetric(elementType: ElementType): boolean {
  const element = elements[elementType];
  return 'symmetric' in element && element.symmetric;
}

isSymmetric('asdf'); // doesn't work

TypeScript <4.9.0

中间函数可用于在推断键时约束对象的值。

type ElementValue = {
  nodes: number;
  symmetric?: boolean;
};

function typedElements<T extends Record<string, ElementValue>>(o: T) {
  return o;
}

const elements = typedElements({
  square: { nodes: 4, symmetric: true },
  triangle: { nodes: 3 },
});

type Elements = typeof elements;
type ElementType = keyof Elements;

function isSymmetric(elementType: ElementType): boolean {
  const element = elements[elementType];
  return 'symmetric' in element && element.symmetric;
}

isSymmetric('asdf'); // doesn't work

另一个更简单的解决方案涉及使用enum而不是复杂的TS类型继承：

type SiteRoute = {
  title: string
  path: string
  isAdmin?: boolean
  disabled?: boolean
}

enum Routes {
    home = "home",
    events = "events",
    contacts = "contacts",
}

const ROUTES_DETAILS: Record<Routes, SiteRoute> = {
    [Routes.home]: {
        title: "Home",
        path: "/",
    },
    [Routes.events]: {
        title: "Events",
        path: "/events",
        disabled: true,

    },
    [Routes.contacts]: {
        title: "Contacts",
        path: "/contacts",
        isAdmin: true,
        disabled: true,
    },
}

ROUTES_DETAILS.home  // ok with autocomplete
ROUTES_DETAILS.asa   // Error: Property 'asa' does not exist on type

这个解决方案可读性更强，使用基本类型和enum。唯一的缺点是enum应该与一个字符串值配对，以便在自动完成中可读。