typescript 错误 : Property '...' is missing in type '...'

Question

我遇到了这段代码的 TypeScript 错误:

let event: KeyboardEvent = {
    preventDefault: () => { },
    stopPropagation: () => { },
    keyCode: 75
};

错误所在:

类型 '{ preventDefault: () => void;停止传播:()=>无效；键码:数字； }' 不可分配给类型 'KeyboardEvent'。
类型 '{ preventDefault: () => void; 中缺少属性 'altKey'；停止传播:()=>无效；键码:数字； }'.

我明白了，它是 TypeScript，它要我提供完整的 KeyboardEvent。但是 KeyboardEvent 的完整定义是:

interface KeyboardEvent extends UIEvent {
    readonly altKey: boolean;
    readonly char: string | null;
    readonly charCode: number;
    readonly ctrlKey: boolean;
    readonly key: string;
    readonly keyCode: number;
    readonly locale: string;
    readonly location: number;
    readonly metaKey: boolean;
    readonly repeat: boolean;
    readonly shiftKey: boolean;
    readonly which: number;
    readonly code: string;
    getModifierState(keyArg: string): boolean;
    initKeyboardEvent(typeArg: string, canBubbleArg: boolean, cancelableArg: boolean, viewArg: Window, keyArg: string, locationArg: number, modifiersListArg: string, repeat: boolean, locale: string): void;
    readonly DOM_KEY_LOCATION_JOYSTICK: number;
    readonly DOM_KEY_LOCATION_LEFT: number;
    readonly DOM_KEY_LOCATION_MOBILE: number;
    readonly DOM_KEY_LOCATION_NUMPAD: number;
    readonly DOM_KEY_LOCATION_RIGHT: number;
    readonly DOM_KEY_LOCATION_STANDARD: number;
}

很多。我正在为单元测试目的创建此事件，我只需要三个属性。处理这个问题的正确方法是什么？我试图避免简单地将其声明为 any 并且我也真的不想定义 21 个属性。

有没有更好的办法？

提前致谢!

Answer 1

尝试转换为所需的类型

let event: KeyboardEvent = {
    preventDefault: () => { },
    stopPropagation: () => { },
    keyCode: 75
} as KeyboardEvent;