redis protocol implement for server

redis-mini-server.js

const net = require('net');
const server = net.createServer();
const CRLF = "\r\n";
const map = new Map();
server.on("connection", (socket) => {
  socket.on("data", (command) => {
    const c = command.toString();
    const cs = c.split(CRLF);
    console.log(cs);
    const com = cs[2];
    const arg1 = cs[4];
    const arg2 = cs[6];
    if (com === "set") {
      set(arg1, arg2);
    }
    if (com === "get") {
      const value = get(arg1);
      if (value == null) {
        socket.write(`$-1${CRLF}`);
        return;
      }
      socket.write(`+${value}${CRLF}`);
      return;
    }
    if (com === "del") {
      del(arg1);
    }
    if (com === "keys") {
      const ks = keys(arg1);
      const len = `*${ks.length}`;
      const r = [];
      ks.forEach((k) => {
        r.push(`$${k.length}`);
        r.push(k);
      });
      r.unshift(len);
      const result = r.join(CRLF);
      console.log(result);
      socket.write(`${result}${CRLF}`);
      return;
    }
    if (com === "quit") {
      socket.end();
      return;
    }
    socket.write("+OK"+CRLF);
  });
});

function set(key, value) {
  map.set(key, value);
}

function get(key) {
  return map.get(key);
}

function del(key) {
  map.delete(key);
}

function keys(pattern) {
  const ks = map.keys();
  if (pattern === "*") {
    return Array.from(ks);
  }
}

server.listen(6379);