Fix terminal freezing self and whole app when internet is disconnected (#5870)

- Remove uses to navigator.onLine as not needed and because that value
  cannot be trusted (see several bug reports on chromium)

- Fix infinite loop when socket is not connected in flush

- Add some simple tests

Signed-off-by: Sebastian Malton <sebastian@malton.name>

src/renderer/api/__tests__/websocket-api.test.ts

@@ -0,0 +1,37 @@
+/**
+ * Copyright (c) OpenLens Authors. All rights reserved.
+ * Licensed under MIT License. See LICENSE in root directory for more information.
+ */
+
+import type { WebSocketEvents } from "../websocket-api";
+import { WebSocketApi } from "../websocket-api";
+
+class TestWebSocketApi extends WebSocketApi<WebSocketEvents> {
+  flush(): void {
+    super.flush();
+  }
+}
+
+describe("WebsocketApi tests", () => {
+  let api: TestWebSocketApi;
+
+  beforeEach(() => {
+    api = new TestWebSocketApi({});
+  });
+
+  describe("before connection", () => {
+    it("does not hang when flush is called", () => {
+      api.flush();
+    });
+
+    describe("when a message has been sent", () => {
+      beforeEach(() => {
+        api.send("a command");
+      });
+
+      it("does not hang when flush is called", () => {
+        api.flush();
+      });
+    });
+  });
+});

src/renderer/api/websocket-api.ts

@@ -94,16 +94,8 @@ export class WebSocketApi<Events extends WebSocketEvents> extends (EventEmitter
     }
   }
 
-  protected getIsConnected(): this is (WebSocketApi<Events> & { socket: WebSocket }) {
-    return this.socket?.readyState === WebSocket.OPEN && this.isOnline;
-  }
-
-  get isConnected() {
-    return this.getIsConnected();
-  }
-
-  get isOnline() {
-    return navigator.onLine;
+  isConnected(): this is (WebSocketApi<Events> & { socket: WebSocket }) {
+    return this.socket?.readyState === WebSocket.OPEN;
   }
 
   connect(url: string) {
@@ -120,7 +112,7 @@ export class WebSocketApi<Events extends WebSocketEvents> extends (EventEmitter
   }
 
   ping() {
-    if (this.isConnected) {
+    if (this.isConnected()) {
       this.send(this.params.pingMessage);
     }
   }
@@ -151,7 +143,7 @@ export class WebSocketApi<Events extends WebSocketEvents> extends (EventEmitter
   }
 
   send(command: string) {
-    if (this.getIsConnected()) {
+    if (this.isConnected()) {
       this.socket.send(command);
     } else {
       this.pendingCommands.push(command);
@@ -159,11 +151,13 @@ export class WebSocketApi<Events extends WebSocketEvents> extends (EventEmitter
   }
 
   protected flush() {
-    for (const command of this.pendingCommands) {
+    const commands = this.pendingCommands;
+
+    this.pendingCommands = [];
+
+    for (const command of commands) {
       this.send(command);
     }
-
-    this.pendingCommands.length = 0;
   }
 
   protected _onOpen(evt: Event) {