fix hanging web socket connections

Author: Alberto Iannaccone

arduino-ide-extension/src/browser/monitor-manager-proxy-client-impl.ts

@@ -58,7 +58,10 @@ export class MonitorManagerProxyClientImpl
    * @param addressPort port of the WebSocket
    */
   async connect(addressPort: number): Promise<void> {
-    if (!!this.webSocket && this.wsPort === addressPort) return;
+    if (!!this.webSocket) {
+      if (this.wsPort === addressPort) return;
+      else this.disconnect();
+    }
     try {
       this.webSocket = new WebSocket(`ws://localhost:${addressPort}`);
     } catch {
@@ -84,6 +87,7 @@ export class MonitorManagerProxyClientImpl
    * Disconnects the WebSocket if connected.
    */
   disconnect(): void {
+    if (!this.webSocket) return;
     try {
       this.webSocket?.close();
       this.webSocket = undefined;

arduino-ide-extension/src/browser/serial/monitor/monitor-view-contribution.tsx

@@ -137,8 +137,10 @@ export class MonitorViewContribution
 
   protected async reset(): Promise<void> {
     const widget = this.tryGetWidget();
-    if (widget) widget.dispose();
-    await this.openView({ activate: true, reveal: true });
+    if (widget) {
+      widget.dispose();
+      await this.openView({ activate: true, reveal: true });
+    }
   }
 
   protected renderAutoScrollButton(): React.ReactNode {

arduino-ide-extension/src/node/monitor-service.ts

@@ -75,7 +75,9 @@ export class MonitorService extends CoreClientAware implements Disposable {
           // data from this monitor, we can freely close
           // and dispose it.
           this.dispose();
+          return;
         }
+        this.updateClientsSettings(this.settings);
       });
 
     this.portMonitorSettings(port.protocol, board.fqbn!).then(
@@ -447,6 +449,7 @@ export class MonitorService extends CoreClientAware implements Disposable {
   }
 
   updateClientsSettings(settings: MonitorSettings): void {
+    this.settings = { ...this.settings, ...settings };
     const command: Monitor.Message = {
       command: Monitor.MiddlewareCommand.ON_SETTINGS_DID_CHANGE,
       data: settings,