the problem that attributes cannot be added to the prototype in ESLint
related codes
Date.prototype.pattern = function (fmt) {
var o = {
"M+": this.getMonth() + 1,
"d+": this.getDate(),
"h+": this.getHours() % 12 === 0 ? 12 : this.getHours() % 12,
"H+": this.getHours(),
"m+": this.getMinutes(),
"s+": this.getSeconds(),
"q+": Math.floor((this.getMonth() + 3) / 3),
"S": this.getMilliseconds()};
var week = {
"0": "/u65e5",
"1": "/u4e00",
"2": "/u4e8c",
"3": "/u4e09",
"4": "/u56db",
"5": "/u4e94",
"6": "/u516d"};
if (/ (y +) / .test (fmt)) {
fmt = fmt.replace(RegExp.$1, (this.getFullYear() + "").substr(4 - RegExp.$1.length));}
if (/ (E+) / .test (fmt)) {
fmt = fmt.replace(RegExp.$1, ((RegExp.$1.length > 1) ? (RegExp.$1.length > 2 ? "/u661f/u671f" : "/u5468") : "") + week[this.getDay() + ""]);}
for (var k in o) {
if (new RegExp("(" + k + ")").test(fmt)) {
fmt = fmt.replace(RegExp.$1, (RegExp.$1.length === 1) ? (o[k]) : (("00" + o[k]).substr(("" + o[k]).length)));
}}
return fmt;
};