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/ipc/index.tsx

@@ -5,7 +5,7 @@ import { Notifications, notificationsStore } from "../components/notifications";
 import { Button } from "../components/button";
 import { isMac } from "../../common/vars";
 import { invalidKubeconfigHandler } from "./invalid-kubeconfig-handler";
-import { clusterStore } from "../../common/cluster-store";
+import { ClusterStore } from "../../common/cluster-store";
 import { navigate } from "../navigation";
 import { entitySettingsURL } from "../components/+entity-settings";
 
@@ -76,7 +76,7 @@ function ListNamespacesForbiddenHandler(event: IpcRendererEvent, ...[clusterId]:
     (
       <div className="flex column gaps">
         <b>Add Accessible Namespaces</b>
-        <p>Cluster <b>{clusterStore.active.name}</b> does not have permissions to list namespaces. Please add the namespaces you have access to.</p>
+        <p>Cluster <b>{ClusterStore.getInstance().active.name}</b> does not have permissions to list namespaces. Please add the namespaces you have access to.</p>
         <div className="flex gaps row align-left box grow">
           <Button active outlined label="Go to Accessible Namespaces Settings" onClick={()=> {
             navigate(entitySettingsURL({ params: { entityId: clusterId }, fragment: "accessible-namespaces" }));

src/renderer/ipc/invalid-kubeconfig-handler.tsx

@@ -1,6 +1,6 @@
 import React from "react";
 import { ipcRenderer, IpcRendererEvent, shell } from "electron";
-import { clusterStore } from "../../common/cluster-store";
+import { ClusterStore } from "../../common/cluster-store";
 import { InvalidKubeConfigArgs, InvalidKubeconfigChannel } from "../../common/ipc/invalid-kubeconfig";
 import { Notifications, notificationsStore } from "../components/notifications";
 import { Button } from "../components/button";
@@ -10,13 +10,13 @@ export const invalidKubeconfigHandler = {
   channel: InvalidKubeconfigChannel,
   listener: InvalidKubeconfigListener,
   verifier: (args: [unknown]): args is InvalidKubeConfigArgs  => {
-    return args.length === 1 && typeof args[0] === "string" && !!clusterStore.getById(args[0]);
+    return args.length === 1 && typeof args[0] === "string" && !!ClusterStore.getInstance().getById(args[0]);
   },
 };
 
 function InvalidKubeconfigListener(event: IpcRendererEvent, ...[clusterId]: InvalidKubeConfigArgs): void {
   const notificationId = `invalid-kubeconfig:${clusterId}`;
-  const cluster = clusterStore.getById(clusterId);
+  const cluster = ClusterStore.getInstance().getById(clusterId);
   const contextName = cluster.name !== cluster.contextName ? `(context: ${cluster.contextName})` : "";
 
   Notifications.error(
@@ -29,7 +29,7 @@ function InvalidKubeconfigListener(event: IpcRendererEvent, ...[clusterId]: Inva
         <p>Do you want to remove the cluster now?</p>
         <div className="flex gaps row align-left box grow">
           <Button active outlined label="Remove" onClick={()=> {
-            clusterStore.removeById(clusterId);
+            ClusterStore.getInstance().removeById(clusterId);
             notificationsStore.remove(notificationId);
           }} />
           <Button active outlined label="Cancel" onClick={() => notificationsStore.remove(notificationId)} />
@@ -42,5 +42,3 @@ function InvalidKubeconfigListener(event: IpcRendererEvent, ...[clusterId]: Inva
     }
   );
 }
-
-