prevent issue with multiple start/stop calls on same device

Author: Garfonso

README.md

@@ -173,6 +173,9 @@ Of course I'm also very glad about issues and pull requests if you find a bug /
 	Placeholder for next versions (this needs to be indented):
 	### __WORK IN PROGRESS__
 -->
+### __WORK IN PROGRESS__
+* prevent issue with multiple start/stop calls on the same device.
+
 ### 0.5.4 (2023-04-28)
 * fix 'Server sent no subprotocol' error and ignore ts warnings.
 

index.js

@@ -140,9 +140,20 @@ class WebSocketClient extends EventEmitter.EventEmitter {
      * Ends socket connection
      */
     disconnect() {
-        if (this._device.socket) {
-            this._device.socket.close();
-            setTimeout(this._device.socket.terminate, 500); //force close after some time.
+        const socket = this._device.socket; //keep copy of socket here. Might want to reconnect, then terminate is not good, might be called on new socket.
+        if (socket && typeof socket.close === 'function') {
+            socket.close();
+            this._device.debug('Socket closing, demanded by calling diconnect()');
+            setTimeout(() => {
+                if (socket && socket.terminate === 'function') {
+                    try {
+                        socket.terminate();
+                        this._device.debug('Socket terminated, demanded by calling diconnect()');
+                    } catch (e) {
+                        this._device.debug('Could not terminate socket: ' + e.stack);
+                    }
+                }
+            }, 500); //force close after some time
         }
         if (this._device.pingHandler) {
             clearTimeout(this._device.pingHandler);