防抖封装方法：

/*** @param {Function} func* @param {number} wait* @param {boolean} immediate* @return {*}*/
export function debounce(func, wait, immediate) {let timeout, args, context, timestamp, resultconst later = function () {// 据上一次触发时间间隔const last = +new Date() - timestamp// 上次被包装函数被调用时间间隔 last 小于设定时间间隔 waitif (last < wait && last > 0) {timeout = setTimeout(later, wait - last)} else {timeout = null// 如果设定为immediate===true，因为开始边界已经调用过了此处无需调用if (!immediate) {result = func.apply(context, args)if (!timeout) context = args = null}}}return function (...args) {context = thistimestamp = +new Date()const callNow = immediate && !timeout// 如果延时不存在，重新设定延时if (!timeout) timeout = setTimeout(later, wait)if (callNow) {result = func.apply(context, args)context = args = null}return result}
}