Node.js中用HSCAN读取Redis哈希遇报错，求正确实现方案

我通过HSET将用户对象存入Redis哈希，代码如下：

async (userObject) => {
    const { phone } = userObject;
    const key = keyGenerator.getUserAuthKey(phone);

    try {
        for (const [field,value] of Object.entries(userObject)) {
            await redisClient.HSET(key,field,value);
        }
        logger.info(`------ user data cached in redis successfully`);
        return true;
    } catch (error) {
        logger.error(`Error in saving user data in redis : ${error.message}`);
        throw error
    }
}

之后编写了HSCAN读取函数，但运行时抛出错误：TypeError: Cannot read properties of undefined (reading 'length')，读取代码如下：

async function readRedisHashUsingHScan(hashKey) {
    let cursor = '0';
    const result = {};

    do {
        const reply = await redisClient.hScan(hashKey, cursor);
        const elements = reply[1]; 
        cursor = reply.cursor;
        for (let i = 0; i < elements.length; i += 2) {
            result[elements[i]] = elements[i + 1];
        }
    } while (cursor !== '0');

    return result;
}

1. 当目标哈希键不存在、哈希为空时，reply[1]会返回undefined，此时读取elements.length会触发类型错误
2. 原代码游标更新逻辑错误：多数Redis客户端（如ioredis）的hScan返回值是[新游标, 字段值数组]结构，而非包含cursor属性的对象，这会导致游标无法正确更新，引发循环异常

async function readRedisHashUsingHScan(hashKey) {
    let cursor = '0';
    const result = {};

    do {
        // 解构hScan返回的游标和字段值数组
        const [newCursor, elements] = await redisClient.hScan(hashKey, cursor);
        cursor = newCursor;

        // 先校验elements是否为有效数组，避免读取undefined的length
        if (Array.isArray(elements) && elements.length > 0) {
            for (let i = 0; i < elements.length; i += 2) {
                const field = elements[i];
                const value = elements[i + 1];
                if (field !== undefined) {
                    result[field] = value;
                }
            }
        }
    } while (cursor !== '0');

    return result;
}

原存储代码循环调用HSET效率较低，可直接利用Redis HSET的批量设置特性，一次完成存储：

async (userObject) => {
    const { phone } = userObject;
    const key = keyGenerator.getUserAuthKey(phone);

    try {
        // 直接传入对象批量设置哈希字段
        await redisClient.HSET(key, userObject);
        logger.info(`------ user data cached in redis successfully`);
        return true;
    } catch (error) {
        logger.error(`Error in saving user data in redis : ${error.message}`);
        throw error
    }
}

内容的提问来源于stack exchange，提问作者18.5