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：