Redis client xrevrange command has an issue with reading n elements from given stream

[dhruvkakadiya]

As per xrevrange documentation, to get number of elements from given stream "COUNT" word needs to be there before actual value which is missing in current code.

Current code:

    client &
    client::xrevrange(const std::string &key, const range_options_t &range_args, const reply_callback_t &reply_callback) {
        std::vector<std::string> cmd = {"XREVRANGE", key, range_args.Start, range_args.Stop};
        if (range_args.Count > 0) {
            cmd.emplace_back(std::to_string(range_args.Count));
        }
        send(cmd, reply_callback);
        return *this;
    }

Fixed code:

    client &
    client::xrevrange(const std::string &key, const range_options_t &range_args, const reply_callback_t &reply_callback) {
        std::vector<std::string> cmd = {"XREVRANGE", key, range_args.Start, range_args.Stop};
        if (range_args.Count > 0) {
            cmd.emplace_back("COUNT");
            cmd.push_back(std::to_string(range_args.Count));
        }
        send(cmd, reply_callback);
        return *this;
    }