GH-6499: Explicitly close the socket onStop.

Otherwise, the channels will be closed with a `checkAliveTimeout` delay
in the electron application, when refreshing the browser window.

Closes: #6499
Signed-off-by: Akos Kitta <kittaakos@typefox.io>

packages/core/src/browser/messaging/messaging-frontend-module.ts

@@ -15,8 +15,10 @@
  ********************************************************************************/
 
 import { ContainerModule } from 'inversify';
+import { FrontendApplicationContribution } from '../frontend-application';
 import { WebSocketConnectionProvider } from './ws-connection-provider';
 
 export const messagingFrontendModule = new ContainerModule(bind => {
     bind(WebSocketConnectionProvider).toSelf().inSingletonScope();
+    bind(FrontendApplicationContribution).toService(WebSocketConnectionProvider);
 });

packages/core/src/browser/messaging/ws-connection-provider.ts

@@ -18,6 +18,7 @@ import { injectable, interfaces, decorate, unmanaged } from 'inversify';
 import { createWebSocketConnection, Logger, ConsoleLogger } from 'vscode-ws-jsonrpc/lib';
 import { ConnectionHandler, JsonRpcProxyFactory, JsonRpcProxy, Emitter, Event } from '../../common';
 import { WebSocketChannel } from '../../common/messaging/web-socket-channel';
+import { FrontendApplicationContribution } from '../frontend-application';
 import { Endpoint } from '../endpoint';
 import ReconnectingWebSocket from 'reconnecting-websocket';
 
@@ -32,7 +33,7 @@ export interface WebSocketOptions {
 }
 
 @injectable()
-export class WebSocketConnectionProvider {
+export class WebSocketConnectionProvider implements FrontendApplicationContribution {
 
     /**
      * Create a proxy object to remote interface of T type
@@ -80,6 +81,12 @@ export class WebSocketConnectionProvider {
         this.socket = socket;
     }
 
+    onStop(): void {
+        // Close the websocket connection `onStop`. Otherwise, the channels will be closed with 30 sec (`MessagingContribution#checkAliveTimeout`) delay.
+        // https://github.com/eclipse-theia/theia/issues/6499
+        this.socket.close();
+    }
+
     /**
      * Create a proxy object to remote interface of T type
      * over a web socket connection for the given path and proxy factory.