这种方法结合了never和省略。这样做的好处是易于理解，如果需要添加更多属性，也易于更新。

interface Base {
  title: string;
  icon: string;
  component?: never;
  click?: never;
}

interface OnlyComponent {
  component: any;
}

interface OnlyClick {
  click: any;
}

export type MenuItem = (Omit<Base, 'component'> & OnlyComponent) | (Omit<Base, 'click'> & OnlyClick);

你可以使用in来缩小MenuItem的一个实例:

const item: MenuItem = {
  title: 'A good title';
  icon: 'fa-plus';
  component: SomeComponent;
};

//...

if('component' in item) {
  const Comp = item.component;
  //...
}

没有多个接口的替代方案是

export type MenuItem = {
  title: string;
  component: any;
  icon: string;
} | {
  title: string;
  click: any;
  icon: string;
};

const item: MenuItem[] = [
  { title: "", icon: "", component: {} },
  { title: "", icon: "", click: "" },
  // Shouldn't this error out because it's passing a property that is not defined
  { title: "", icon: "", click: "", component: {} },
  // Does error out :)
  { title: "", icon: "" }
];

我在如何创建一个需要设置单个属性的Partial-like中问过类似的问题

上面的内容可以简化，但它可能更容易阅读，也可能不容易

export type MenuItem = {
  title: string;
  icon: string;
} & (
 {component: any} | {click: string}
)

注意，这些都不会阻止你同时添加两者，因为TypeScript确实允许在使用AND/OR的对象上添加额外的属性，请参阅https://github.com/Microsoft/TypeScript/issues/15447

在TypeScript 2.8中添加的Exclude类型的帮助下，提供了一种要求至少一组属性中的一个的通用方法:

type RequireAtLeastOne<T, Keys extends keyof T = keyof T> =
    Pick<T, Exclude<keyof T, Keys>> 
    & {
        [K in Keys]-?: Required<Pick<T, K>> & Partial<Pick<T, Exclude<Keys, K>>>
    }[Keys]

要求提供一个且仅提供一个的部分而非绝对的方法是:

type RequireOnlyOne<T, Keys extends keyof T = keyof T> =
    Pick<T, Exclude<keyof T, Keys>>
    & {
        [K in Keys]-?:
            Required<Pick<T, K>>
            & Partial<Record<Exclude<Keys, K>, undefined>>
    }[Keys]

下面是一个TypeScript游乐场链接，展示了两者的作用。

RequireOnlyOne的警告是TypeScript在编译时并不总是知道运行时存在的每个属性。因此，显然RequireOnlyOne不能做任何事情来防止它不知道的额外属性。我提供了一个示例，说明RequireOnlyOne如何错过playground链接末尾的内容。

使用以下示例快速概述它的工作原理:

interface MenuItem {
  title: string;
  component?: number;
  click?: number;
  icon: string;
}

type ClickOrComponent = RequireAtLeastOne<MenuItem, 'click' | 'component'>

Pick<T, Exclude<keyof T, Keys>> from RequireAtLeastOne becomes { title: string, icon: string}, which are the unchanged properties of the keys not included in 'click' | 'component' { [K in Keys]-?: Required<Pick<T, K>> & Partial<Pick<T, Exclude<Keys, K>>> }[Keys] from RequireAtLeastOne becomes { component: Required<{ component?: number }> & { click?: number }, click: Required<{ click?: number }> & { component?: number } }[Keys] Which becomes { component: { component: number, click?: number }, click: { click: number, component?: number } }['component' | 'click'] Which finally becomes {component: number, click?: number} | {click: number, component?: number} The intersection of steps 1 and 2 above { title: string, icon: string} & ({component: number, click?: number} | {click: number, component?: number}) simplifies to { title: string, icon: string, component: number, click?: number} | { title: string, icon: string, click: number, component?: number}

这里有一个简单的方法来实现其中一个，但不是两个

type MenuItem =  {
  title: string;
  component: any;
  click?: never;
  icon: string;
} | {
  title: string;
  component?: never;
  click: any;
  icon: string;
}

// good
const menuItemWithComponent: MenuItem = {
  title: 'title',
  component: "my component",
  icon: "icon"
}

// good
const menuItemWithClick: MenuItem = {
  title: 'title',
  click: "my click",
  icon: "icon"
}

// compile error
const menuItemWithBoth: MenuItem = {
  title: 'title',
  click: "my click",
  component: "my click",
  icon: "icon"
}

还有另一个解决方案:

type RequiredKeys<T, K extends keyof T> = Required<Pick<T, K>> & Omit<T, K>;

type MenuItem2 = RequiredKeys<MenuItem, "component" | "click">;

不是用一个接口，因为类型没有条件逻辑，不能相互依赖，但你可以通过分离接口:

export interface BaseMenuItem {
  title: string;
  icon: string;
}

export interface ComponentMenuItem extends BaseMenuItem {
  component: any;
}

export interface ClickMenuItem extends BaseMenuItem {
    click: any;
}

export type MenuItem = ComponentMenuItem | ClickMenuItem;