自定义油门单元测试

Question

我有以下测试：

import { throttle } from "./event";

jest.useFakeTimers();

it('mock setTimeout test', () => {
    const mockedFunction = jest.fn();
    throttle(mockedFunction, 1);
    expect(setTimeout).toHaveBeenLastCalledWith(mockedFunction, 1000);
    expect(setTimeout).toHaveBeenCalledTimes(1);
});

油门在哪里：

export const throttle = (func, wait) => {
    let timer = null;
    return function(...args) {
        if (timer === null) {
            timer = setTimeout(() => {
                func.apply(this, args);
                timer = null;
            }, wait); 
        }
    };
};

但测试失败：

Answer 1

错误就在这里，throttle 会为你创建一个新函数，“添加”一个“等待之前”功能......你从来没有调用过它

  throttle(mockedFunction, 1)();