面试官：策略模式有使用过吗？我：没有......（下）

validator.add(username, [
    {
        strategy: "isEmpty",
        msg: "用户名不能为空"
    },
    {
        strategy: 'minLength:6',
        msg: '密码不能少于 6 位'
    }
]);

let infoForm = {
    username: "阿斯顿发生的",
    password: "ss1sdf",
    tel: 15829485647,
};
var strategies = {
    isEmpty: function (val, msg) {
        if (!val) return msg;
    },
    minLength: function (val, length, msg) {
        if (val.length < length) return msg;
    },
    isTel: function (val, msg) {
        if (!/(^1[3|5|8][0-9]{9}$)/.test(val)) return msg;
    },
};
var validFn = function () {
    var validator = new Validator();
    let { username, password, tel } = infoForm;
    validator.add(username, [
        {
            strategy: "isEmpty",
            msg: "用户名不能为空",
        },
        {
            strategy: "minLength:6",
            msg: "密码不能少于 6 位",
        },
    ]);
    validator.add(password, [
        {
            strategy: "minLength:6",
            msg: "密码不能少于 6 位",
        },
    ]);
    validator.add(tel, [
        {
            strategy: "isTel",
            msg: "手机号码格式不正确",
        },
    ]);
    var msg = validator.start();
    return msg;
};
class Validator {
    constructor() {
        this.cache = [];
    }
    add(attr, rules) {
        for (let i = 0; i < rules.length; i++) {
            var rule = rules[i];
            var ruleArr = rule.strategy.split(":");
            var msg = rule.msg;
            var cacheItem = this.createCacheItem(ruleArr, attr, msg);
            this.cache.push(cacheItem);
        }
    }
    start() {
        for (let i = 0; i < this.cache.length; i++) {
            var msg = this.cache[i]();
            if (msg) return msg;
        }
    }
    createCacheItem(ruleArr, attr, msg) {
        return function () {
            var strategy = ruleArr.shift();
            ruleArr.unshift(attr);
            ruleArr.push(msg);
            return strategies[strategy].apply(attr, ruleArr);
        };
    }
}
function submit() {
    let msg = validFn();
    if (msg) {
        Toast(msg);
        return false;
    }
    console.log("verify success");
    // .....
}
submit();