js封装一个websocket，要求有心跳重连机制

好的，下面是一个简单的 JavaScript WebSocket 封装代码，它包含心跳重连机制：

class WebSocketClient {
  constructor(url, options = {}) {
    this.url = url;
    this.options = options;
    this.reconnectInterval = options.reconnectInterval || 1000;
    this.heartbeatInterval = options.heartbeatInterval || 5000;
    this.onopen = options.onopen || function() {};
    this.onmessage = options.onmessage || function() {};
    this.onclose = options.onclose || function() {};
    this.onerror = options.onerror || function() {};
    this.connect();
  }

  connect() {
    this.socket = new WebSocket(this.url);
    this.socket.onopen = () => {
      console.log('WebSocket connected');
      this.onopen();
      this.startHeartbeat();
    };
    this.socket.onmessage = (event) => {
      console.log(`WebSocket message received: ${event.data}`);
      this.onmessage(event);
    };
    this.socket.onclose = (event) => {
      console.log(`WebSocket closed with code ${event.code}`);
      this.onclose(event);
      setTimeout(() => {
        console.log('WebSocket reconnecting...');
        this.connect();
      }, this.reconnectInterval);
    };
    this.socket.onerror = (error) => {
      console.error(`WebSocket error: ${error.message}`);
      this.onerror(error);
    };
  }

  send(data) {
    this.socket.send(data);
  }

  startHeartbeat() {
    this.heartbeatTimer = setInterval(() => {
      if (this.socket.readyState === WebSocket.OPEN) {
        this.send('ping');
      }
    }, this.heartbeatInterval);
  }

  stopHeartbeat() {
    clearInterval(this.heartbeatTimer);
  }

  close() {
    this.stopHeartbeat();
    this.socket.close();
  }
}

使用方法如下：

const ws = new WebSocketClient('ws://localhost:8080', {
  onopen: () => {
    console.log('WebSocket opened');
  },
  onmessage: (event) => {
    if (event.data === 'ping') {
      console.log('WebSocket heartbeat received');
    } else {
      console.log(`WebSocket message received: ${event.data}`);
    }
  },
  onclose: () => {
    console.log('WebSocket closed');
  },
  onerror: (error) => {
    console.error(`WebSocket error: ${error.message}`);
  },
  reconnectInterval: 1000,
  heartbeatInterval: 5000,
});

// 发送消息
ws.send('hello');

// 关闭连接
ws.close();

该代码在创建 `WebSocketClient` 对象时会自动连接 WebSocket，并启动心跳检测。当 WebSocket 断开连接时，会自动重连。可以通过调用 `send` 方法发送消息，通过调用 `close` 方法关闭连接。