Fixing Singleton typing to correctly return child class (#1914)

- Add distinction between `getInstance` and `getInstanceOrCreate` since
  it is not always possible to create an instance (since you might not
  know the correct arguments)

- Remove all the `export const *Store = *Store.getInstance<*Store>();`
  calls as it defeats the purpose of `Singleton`. Plus with the typing
  changes the appropriate `*Store.getInstance()` is "short enough".

- Special case the two extension export facades to not need to use
  `getInstanceOrCreate`. Plus since they are just facades it is always
  possible to create them.

- Move some other types to be also `Singleton`'s: ExtensionLoader,
  ExtensionDiscovery, ThemeStore, LocalizationStore, ...

- Fixed dev-run always using the same port with electron inspect

- Update Store documentation with new recommendations about creating
  instances of singletons

- Fix all unit tests to create their dependent singletons

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

src/renderer/lens-app.tsx

@@ -2,14 +2,14 @@ import "../common/system-ca";
 import React from "react";
 import { Route, Router, Switch } from "react-router";
 import { observer } from "mobx-react";
-import { userStore } from "../common/user-store";
+import { UserStore } from "../common/user-store";
 import { history } from "./navigation";
 import { ClusterManager } from "./components/cluster-manager";
 import { ErrorBoundary } from "./components/error-boundary";
 import { WhatsNew, whatsNewRoute } from "./components/+whats-new";
 import { Notifications } from "./components/notifications";
 import { ConfirmDialog } from "./components/confirm-dialog";
-import { extensionLoader } from "../extensions/extension-loader";
+import { ExtensionLoader } from "../extensions/extension-loader";
 import { broadcastMessage } from "../common/ipc";
 import { CommandContainer } from "./components/command-palette/command-container";
 import { LensProtocolRouterRenderer, bindProtocolAddRouteHandlers } from "./protocol-handler";
@@ -24,15 +24,12 @@ import { reaction } from "mobx";
 export class LensApp extends React.Component {
   static async init() {
     catalogEntityRegistry.init();
-    extensionLoader.loadOnClusterManagerRenderer();
-    LensProtocolRouterRenderer.getInstance<LensProtocolRouterRenderer>().init();
+    ExtensionLoader.getInstance().loadOnClusterManagerRenderer();
+    LensProtocolRouterRenderer.getInstanceOrCreate().init();
     bindProtocolAddRouteHandlers();
-    window.addEventListener("offline", () => {
-      broadcastMessage("network:offline");
-    });
-    window.addEventListener("online", () => {
-      broadcastMessage("network:online");
-    });
+
+    window.addEventListener("offline", () => broadcastMessage("network:offline"));
+    window.addEventListener("online", () => broadcastMessage("network:online"));
 
     registerIpcHandlers();
     ipcRenderer.send(IpcRendererNavigationEvents.LOADED);
@@ -55,7 +52,7 @@ export class LensApp extends React.Component {
       <Router history={history}>
         <ErrorBoundary>
           <Switch>
-            {userStore.isNewVersion && <Route component={WhatsNew}/>}
+            {UserStore.getInstance().isNewVersion && <Route component={WhatsNew}/>}
             <Route component={WhatsNew} {...whatsNewRoute}/>
             <Route component={ClusterManager}/>
           </Switch>