Node.js v22 原生能力实战：WebSocket + fetch + node:sqlite 协作看板

// npm install ws（WebSocket 服务端暂无内置实现，Node 原生仅提供客户端）
import { WebSocketServer } from 'ws';
import { DatabaseSync } from 'node:sqlite';
import { createServer } from 'node:http';

const db = new DatabaseSync(':memory:');
db.exec(`CREATE TABLE tasks(id INTEGER PRIMARY KEY, title TEXT, done INTEGER)`);

const server = createServer();
const wss = new WebSocketServer({ server });

wss.on('connection', (ws) => {
  ws.on('message', (raw) => {
    const msg = JSON.parse(raw.toString());
    if (msg.type === 'add') {
      db.prepare('INSERT INTO tasks(title, done) VALUES(?, 0)').run(msg.title);
    }
    const tasks = db.prepare('SELECT * FROM tasks').all();
    const payload = JSON.stringify({ type: 'sync', tasks });
    for (const c of wss.clients) c.send(payload); // 广播一致性
  });
});

server.listen(3000);

const ws = new WebSocket('ws://localhost:3000');
ws.onmessage = (e) => {
  const { tasks } = JSON.parse(e.data);
  render(tasks); // 全量重渲染，保持各端最终一致
};
document.querySelector('#add').onclick = () =>
  ws.send(JSON.stringify({ type: 'add', title: input.value }));

const res = await fetch('https://api.example.com/weather');
const { temp } = await res.json();
db.prepare('INSERT INTO tasks(title, done) VALUES(?, 0)').run(`天气播报：${temp}℃`);