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/common/__tests__/cluster-store.test.ts

@@ -4,8 +4,9 @@ import yaml from "js-yaml";
 import { Cluster } from "../../main/cluster";
 import { ClusterStore, getClusterIdFromHost } from "../cluster-store";
 import { Console } from "console";
+import { stdout, stderr } from "process";
 
-console = new Console(process.stdout, process.stderr); // fix mockFS
+console = new Console(stdout, stderr);
 
 const testDataIcon = fs.readFileSync("test-data/cluster-store-migration-icon.png");
 const kubeconfig = `
@@ -47,10 +48,8 @@ jest.mock("electron", () => {
   };
 });
 
-let clusterStore: ClusterStore;
-
 describe("empty config", () => {
-  beforeEach(() => {
+  beforeEach(async () => {
     ClusterStore.resetInstance();
     const mockOpts = {
       "tmp": {
@@ -59,9 +58,8 @@ describe("empty config", () => {
     };
 
     mockFs(mockOpts);
-    clusterStore = ClusterStore.getInstance<ClusterStore>();
 
-    return clusterStore.load();
+    await ClusterStore.getInstanceOrCreate().load();
   });
 
   afterEach(() => {
@@ -70,7 +68,7 @@ describe("empty config", () => {
 
   describe("with foo cluster added", () => {
     beforeEach(() => {
-      clusterStore.addCluster(
+      ClusterStore.getInstance().addCluster(
         new Cluster({
           id: "foo",
           contextName: "foo",
@@ -85,7 +83,7 @@ describe("empty config", () => {
     });
 
     it("adds new cluster to store", async () => {
-      const storedCluster = clusterStore.getById("foo");
+      const storedCluster = ClusterStore.getInstance().getById("foo");
 
       expect(storedCluster.id).toBe("foo");
       expect(storedCluster.preferences.terminalCWD).toBe("/tmp");
@@ -94,19 +92,19 @@ describe("empty config", () => {
     });
 
     it("removes cluster from store", async () => {
-      await clusterStore.removeById("foo");
-      expect(clusterStore.getById("foo")).toBeNull();
+      await ClusterStore.getInstance().removeById("foo");
+      expect(ClusterStore.getInstance().getById("foo")).toBeNull();
     });
 
     it("sets active cluster", () => {
-      clusterStore.setActive("foo");
-      expect(clusterStore.active.id).toBe("foo");
+      ClusterStore.getInstance().setActive("foo");
+      expect(ClusterStore.getInstance().active.id).toBe("foo");
     });
   });
 
   describe("with prod and dev clusters added", () => {
     beforeEach(() => {
-      clusterStore.addClusters(
+      ClusterStore.getInstance().addClusters(
         new Cluster({
           id: "prod",
           contextName: "foo",
@@ -127,8 +125,8 @@ describe("empty config", () => {
     });
 
     it("check if store can contain multiple clusters", () => {
-      expect(clusterStore.hasClusters()).toBeTruthy();
-      expect(clusterStore.clusters.size).toBe(2);
+      expect(ClusterStore.getInstance().hasClusters()).toBeTruthy();
+      expect(ClusterStore.getInstance().clusters.size).toBe(2);
     });
 
     it("check if cluster's kubeconfig file saved", () => {
@@ -178,9 +176,8 @@ describe("config with existing clusters", () => {
     };
 
     mockFs(mockOpts);
-    clusterStore = ClusterStore.getInstance<ClusterStore>();
 
-    return clusterStore.load();
+    return ClusterStore.getInstanceOrCreate().load();
   });
 
   afterEach(() => {
@@ -188,24 +185,24 @@ describe("config with existing clusters", () => {
   });
 
   it("allows to retrieve a cluster", () => {
-    const storedCluster = clusterStore.getById("cluster1");
+    const storedCluster = ClusterStore.getInstance().getById("cluster1");
 
     expect(storedCluster.id).toBe("cluster1");
     expect(storedCluster.preferences.terminalCWD).toBe("/foo");
   });
 
   it("allows to delete a cluster", () => {
-    clusterStore.removeById("cluster2");
-    const storedCluster = clusterStore.getById("cluster1");
+    ClusterStore.getInstance().removeById("cluster2");
+    const storedCluster = ClusterStore.getInstance().getById("cluster1");
 
     expect(storedCluster).toBeTruthy();
-    const storedCluster2 = clusterStore.getById("cluster2");
+    const storedCluster2 = ClusterStore.getInstance().getById("cluster2");
 
     expect(storedCluster2).toBeNull();
   });
 
   it("allows getting all of the clusters", async () => {
-    const storedClusters = clusterStore.clustersList;
+    const storedClusters = ClusterStore.getInstance().clustersList;
 
     expect(storedClusters.length).toBe(3);
     expect(storedClusters[0].id).toBe("cluster1");
@@ -216,7 +213,7 @@ describe("config with existing clusters", () => {
   });
 
   it("marks owned cluster disabled by default", () => {
-    const storedClusters = clusterStore.clustersList;
+    const storedClusters = ClusterStore.getInstance().clustersList;
 
     expect(storedClusters[0].enabled).toBe(true);
     expect(storedClusters[2].enabled).toBe(false);
@@ -276,9 +273,8 @@ users:
     };
 
     mockFs(mockOpts);
-    clusterStore = ClusterStore.getInstance<ClusterStore>();
 
-    return clusterStore.load();
+    return ClusterStore.getInstanceOrCreate().load();
   });
 
   afterEach(() => {
@@ -286,7 +282,7 @@ users:
   });
 
   it("does not enable clusters with invalid kubeconfig", () => {
-    const storedClusters = clusterStore.clustersList;
+    const storedClusters = ClusterStore.getInstance().clustersList;
 
     expect(storedClusters.length).toBe(2);
     expect(storedClusters[0].enabled).toBeFalsy;
@@ -319,9 +315,8 @@ describe("pre 2.0 config with an existing cluster", () => {
     };
 
     mockFs(mockOpts);
-    clusterStore = ClusterStore.getInstance<ClusterStore>();
 
-    return clusterStore.load();
+    return ClusterStore.getInstanceOrCreate().load();
   });
 
   afterEach(() => {
@@ -329,7 +324,7 @@ describe("pre 2.0 config with an existing cluster", () => {
   });
 
   it("migrates to modern format with kubeconfig in a file", async () => {
-    const config = clusterStore.clustersList[0].kubeConfigPath;
+    const config = ClusterStore.getInstance().clustersList[0].kubeConfigPath;
 
     expect(fs.readFileSync(config, "utf8")).toContain(`"contexts":[]`);
   });
@@ -347,16 +342,51 @@ describe("pre 2.6.0 config with a cluster that has arrays in auth config", () =>
             }
           },
           cluster1: {
-            kubeConfig: "apiVersion: v1\nclusters:\n- cluster:\n    server: https://10.211.55.6:8443\n  name: minikube\ncontexts:\n- context:\n    cluster: minikube\n    user: minikube\n  name: minikube\ncurrent-context: minikube\nkind: Config\npreferences: {}\nusers:\n- name: minikube\n  user:\n    client-certificate: /Users/kimmo/.minikube/client.crt\n    client-key: /Users/kimmo/.minikube/client.key\n    auth-provider:\n      config:\n        access-token:\n          - should be string\n        expiry:\n          - should be string\n"
+            kubeConfig: JSON.stringify({
+              apiVersion: "v1",
+              clusters: [{
+                cluster: {
+                  server: "https://10.211.55.6:8443",
+                },
+                name: "minikube",
+              }],
+              contexts: [{
+                context: {
+                  cluster: "minikube",
+                  user: "minikube",
+                  name: "minikube",
+                },
+                name: "minikube",
+              }],
+              "current-context": "minikube",
+              kind: "Config",
+              preferences: {},
+              users: [{
+                name: "minikube",
+                user: {
+                  "client-certificate": "/Users/foo/.minikube/client.crt",
+                  "client-key": "/Users/foo/.minikube/client.key",
+                  "auth-provider": {
+                    config: {
+                      "access-token": [
+                        "should be string"
+                      ],
+                      expiry: [
+                        "should be string"
+                      ],
+                    }
+                  }
+                },
+              }]
+            }),
           },
         })
       }
     };
 
     mockFs(mockOpts);
-    clusterStore = ClusterStore.getInstance<ClusterStore>();
 
-    return clusterStore.load();
+    return ClusterStore.getInstanceOrCreate().load();
   });
 
   afterEach(() => {
@@ -364,10 +394,12 @@ describe("pre 2.6.0 config with a cluster that has arrays in auth config", () =>
   });
 
   it("replaces array format access token and expiry into string", async () => {
-    const file = clusterStore.clustersList[0].kubeConfigPath;
+    const file = ClusterStore.getInstance().clustersList[0].kubeConfigPath;
     const config = fs.readFileSync(file, "utf8");
     const kc = yaml.safeLoad(config);
 
+    console.log(kc);
+
     expect(kc.users[0].user["auth-provider"].config["access-token"]).toBe("should be string");
     expect(kc.users[0].user["auth-provider"].config["expiry"]).toBe("should be string");
   });
@@ -397,9 +429,8 @@ describe("pre 2.6.0 config with a cluster icon", () => {
     };
 
     mockFs(mockOpts);
-    clusterStore = ClusterStore.getInstance<ClusterStore>();
 
-    return clusterStore.load();
+    return ClusterStore.getInstanceOrCreate().load();
   });
 
   afterEach(() => {
@@ -407,7 +438,7 @@ describe("pre 2.6.0 config with a cluster icon", () => {
   });
 
   it("moves the icon into preferences", async () => {
-    const storedClusterData = clusterStore.clustersList[0];
+    const storedClusterData = ClusterStore.getInstance().clustersList[0];
 
     expect(storedClusterData.hasOwnProperty("icon")).toBe(false);
     expect(storedClusterData.preferences.hasOwnProperty("icon")).toBe(true);
@@ -437,9 +468,8 @@ describe("for a pre 2.7.0-beta.0 config without a workspace", () => {
     };
 
     mockFs(mockOpts);
-    clusterStore = ClusterStore.getInstance<ClusterStore>();
 
-    return clusterStore.load();
+    return ClusterStore.getInstanceOrCreate().load();
   });
 
   afterEach(() => {
@@ -474,9 +504,8 @@ describe("pre 3.6.0-beta.1 config with an existing cluster", () => {
     };
 
     mockFs(mockOpts);
-    clusterStore = ClusterStore.getInstance<ClusterStore>();
 
-    return clusterStore.load();
+    return ClusterStore.getInstanceOrCreate().load();
   });
 
   afterEach(() => {
@@ -484,13 +513,13 @@ describe("pre 3.6.0-beta.1 config with an existing cluster", () => {
   });
 
   it("migrates to modern format with kubeconfig in a file", async () => {
-    const config = clusterStore.clustersList[0].kubeConfigPath;
+    const config = ClusterStore.getInstance().clustersList[0].kubeConfigPath;
 
     expect(fs.readFileSync(config, "utf8")).toBe(minimalValidKubeConfig);
   });
 
   it("migrates to modern format with icon not in file", async () => {
-    const { icon } = clusterStore.clustersList[0].preferences;
+    const { icon } = ClusterStore.getInstance().clustersList[0].preferences;
 
     expect(icon.startsWith("data:;base64,")).toBe(true);
   });

src/common/__tests__/event-bus.test.ts

@@ -1,4 +1,8 @@
 import { appEventBus, AppEvent } from "../event-bus";
+import { Console } from "console";
+import { stdout, stderr } from "process";
+
+console = new Console(stdout, stderr);
 
 describe("event bus tests", () => {
   describe("emit", () => {

src/common/__tests__/hotbar-store.test.ts

@@ -1,8 +1,12 @@
 import mockFs from "mock-fs";
-import { HotbarStore, hotbarStore } from "../hotbar-store";
+import { ClusterStore } from "../cluster-store";
+import { HotbarStore } from "../hotbar-store";
 
 describe("HotbarStore", () => {
   beforeEach(() => {
+    ClusterStore.resetInstance();
+    ClusterStore.getInstanceOrCreate();
+
     HotbarStore.resetInstance();
     mockFs({ tmp: { "lens-hotbar-store.json": "{}" } });
   });
@@ -13,8 +17,8 @@ describe("HotbarStore", () => {
 
   describe("load", () => {
     it("loads one hotbar by default", () => {
-      hotbarStore.load();
-      expect(hotbarStore.hotbars.length).toEqual(1);
+      HotbarStore.getInstanceOrCreate().load();
+      expect(HotbarStore.getInstance().hotbars.length).toEqual(1);
     });
   });
 });

src/common/__tests__/search-store.test.ts

@@ -1,4 +1,8 @@
 import { SearchStore } from "../search-store";
+import { Console } from "console";
+import { stdout, stderr } from "process";
+
+console = new Console(stdout, stderr);
 
 let searchStore: SearchStore = null;
 const logs = [

src/common/__tests__/user-store.test.ts

@@ -10,7 +10,7 @@ jest.mock("electron", () => {
       getVersion: () => "99.99.99",
       getPath: () => "tmp",
       getLocale: () => "en",
-      setLoginItemSettings: jest.fn(),
+      setLoginItemSettings: (): void => void 0,
     }
   };
 });
@@ -18,12 +18,19 @@ jest.mock("electron", () => {
 import { UserStore } from "../user-store";
 import { SemVer } from "semver";
 import electron from "electron";
+import { stdout, stderr } from "process";
+
+console = new Console(stdout, stderr);
 
 describe("user store tests", () => {
   describe("for an empty config", () => {
     beforeEach(() => {
       UserStore.resetInstance();
-      mockFs({ tmp: { "config.json": "{}" } });
+      mockFs({ tmp: { "config.json": "{}", "kube_config": "{}" } });
+
+      (UserStore.getInstanceOrCreate() as any).refreshNewContexts = jest.fn(() => Promise.resolve());
+
+      return UserStore.getInstance().load();
     });
 
     afterEach(() => {
@@ -31,14 +38,14 @@ describe("user store tests", () => {
     });
 
     it("allows setting and retrieving lastSeenAppVersion", () => {
-      const us = UserStore.getInstance<UserStore>();
+      const us = UserStore.getInstance();
 
       us.lastSeenAppVersion = "1.2.3";
       expect(us.lastSeenAppVersion).toBe("1.2.3");
     });
 
     it("allows adding and listing seen contexts", () => {
-      const us = UserStore.getInstance<UserStore>();
+      const us = UserStore.getInstance();
 
       us.seenContexts.add("foo");
       expect(us.seenContexts.size).toBe(1);
@@ -51,7 +58,7 @@ describe("user store tests", () => {
     });
 
     it("allows setting and getting preferences", () => {
-      const us = UserStore.getInstance<UserStore>();
+      const us = UserStore.getInstance();
 
       us.preferences.httpsProxy = "abcd://defg";
 
@@ -63,7 +70,7 @@ describe("user store tests", () => {
     });
 
     it("correctly resets theme to default value", async () => {
-      const us = UserStore.getInstance<UserStore>();
+      const us = UserStore.getInstance();
 
       us.isLoaded = true;
 
@@ -73,7 +80,7 @@ describe("user store tests", () => {
     });
 
     it("correctly calculates if the last seen version is an old release", () => {
-      const us = UserStore.getInstance<UserStore>();
+      const us = UserStore.getInstance();
 
       expect(us.isNewVersion).toBe(true);
 
@@ -94,6 +101,8 @@ describe("user store tests", () => {
           })
         }
       });
+
+      return UserStore.getInstanceOrCreate().load();
     });
 
     afterEach(() => {
@@ -101,7 +110,7 @@ describe("user store tests", () => {
     });
 
     it("sets last seen app version to 0.0.0", () => {
-      const us = UserStore.getInstance<UserStore>();
+      const us = UserStore.getInstance();
 
       expect(us.lastSeenAppVersion).toBe("0.0.0");
     });

src/common/catalog-entities/kubernetes-cluster.ts

@@ -3,7 +3,7 @@ import { observable } from "mobx";
 import { catalogCategoryRegistry } from "../catalog-category-registry";
 import { CatalogCategory, CatalogEntity, CatalogEntityActionContext, CatalogEntityAddMenuContext, CatalogEntityContextMenuContext, CatalogEntityData, CatalogEntityMetadata, CatalogEntityStatus } from "../catalog-entity";
 import { clusterDisconnectHandler } from "../cluster-ipc";
-import { clusterStore } from "../cluster-store";
+import { ClusterStore } from "../cluster-store";
 import { requestMain } from "../ipc";
 
 export type KubernetesClusterSpec = {
@@ -56,7 +56,7 @@ export class KubernetesCluster implements CatalogEntity {
         icon: "delete",
         title: "Delete",
         onlyVisibleForSource: "local",
-        onClick: async () => clusterStore.removeById(this.metadata.uid),
+        onClick: async () => ClusterStore.getInstance().removeById(this.metadata.uid),
         confirm: {
           message: `Remove Kubernetes Cluster "${this.metadata.name} from Lens?`
         }
@@ -68,7 +68,7 @@ export class KubernetesCluster implements CatalogEntity {
         icon: "link_off",
         title: "Disconnect",
         onClick: async () => {
-          clusterStore.deactivate(this.metadata.uid);
+          ClusterStore.getInstance().deactivate(this.metadata.uid);
           requestMain(clusterDisconnectHandler, this.metadata.uid);
         }
       });

src/common/cluster-ipc.ts

@@ -1,5 +1,5 @@
 import { handleRequest } from "./ipc";
-import { ClusterId, clusterStore } from "./cluster-store";
+import { ClusterId, ClusterStore } from "./cluster-store";
 import { appEventBus } from "./event-bus";
 import { ResourceApplier } from "../main/resource-applier";
 import { ipcMain, IpcMainInvokeEvent } from "electron";
@@ -11,10 +11,9 @@ export const clusterRefreshHandler = "cluster:refresh";
 export const clusterDisconnectHandler = "cluster:disconnect";
 export const clusterKubectlApplyAllHandler = "cluster:kubectl-apply-all";
 
-
 if (ipcMain) {
   handleRequest(clusterActivateHandler, (event, clusterId: ClusterId, force = false) => {
-    const cluster = clusterStore.getById(clusterId);
+    const cluster = ClusterStore.getInstance().getById(clusterId);
 
     if (cluster) {
       return cluster.activate(force);
@@ -22,7 +21,7 @@ if (ipcMain) {
   });
 
   handleRequest(clusterSetFrameIdHandler, (event: IpcMainInvokeEvent, clusterId: ClusterId) => {
-    const cluster = clusterStore.getById(clusterId);
+    const cluster = ClusterStore.getInstance().getById(clusterId);
 
     if (cluster) {
       clusterFrameMap.set(cluster.id, { frameId: event.frameId, processId: event.processId });
@@ -32,14 +31,14 @@ if (ipcMain) {
   });
 
   handleRequest(clusterRefreshHandler, (event, clusterId: ClusterId) => {
-    const cluster = clusterStore.getById(clusterId);
+    const cluster = ClusterStore.getInstance().getById(clusterId);
 
     if (cluster) return cluster.refresh({ refreshMetadata: true });
   });
 
   handleRequest(clusterDisconnectHandler, (event, clusterId: ClusterId) => {
     appEventBus.emit({name: "cluster", action: "stop"});
-    const cluster = clusterStore.getById(clusterId);
+    const cluster = ClusterStore.getInstance().getById(clusterId);
 
     if (cluster) {
       cluster.disconnect();
@@ -49,7 +48,7 @@ if (ipcMain) {
 
   handleRequest(clusterKubectlApplyAllHandler, (event, clusterId: ClusterId, resources: string[]) => {
     appEventBus.emit({name: "cluster", action: "kubectl-apply-all"});
-    const cluster = clusterStore.getById(clusterId);
+    const cluster = ClusterStore.getInstance().getById(clusterId);
 
     if (cluster) {
       const applier = new ResourceApplier(cluster);

src/common/cluster-store.ts

@@ -112,7 +112,7 @@ export class ClusterStore extends BaseStore<ClusterStoreModel> {
 
   private static stateRequestChannel = "cluster:states";
 
-  private constructor() {
+  constructor() {
     super({
       configName: "lens-cluster-store",
       accessPropertiesByDotNotation: false, // To make dots safe in cluster context names
@@ -337,8 +337,6 @@ export class ClusterStore extends BaseStore<ClusterStoreModel> {
   }
 }
 
-export const clusterStore = ClusterStore.getInstance<ClusterStore>();
-
 export function getClusterIdFromHost(host: string): ClusterId | undefined {
   // e.g host == "%clusterId.localhost:45345"
   const subDomains = host.split(":")[0].split(".");
@@ -355,5 +353,5 @@ export function getHostedClusterId() {
 }
 
 export function getHostedCluster(): Cluster {
-  return clusterStore.getById(getHostedClusterId());
+  return ClusterStore.getInstance().getById(getHostedClusterId());
 }

src/common/hotbar-store.ts

@@ -23,7 +23,7 @@ export interface HotbarStoreModel {
 export class HotbarStore extends BaseStore<HotbarStoreModel> {
   @observable hotbars: Hotbar[] = [];
 
-  private constructor() {
+  constructor() {
     super({
       configName: "lens-hotbar-store",
       accessPropertiesByDotNotation: false, // To make dots safe in cluster context names
@@ -67,5 +67,3 @@ export class HotbarStore extends BaseStore<HotbarStoreModel> {
     });
   }
 }
-
-export const hotbarStore = HotbarStore.getInstance<HotbarStore>();

src/common/protocol-handler/router.ts

@@ -5,8 +5,8 @@ import { pathToRegexp } from "path-to-regexp";
 import logger from "../../main/logger";
 import Url from "url-parse";
 import { RoutingError, RoutingErrorType } from "./error";
-import { extensionsStore } from "../../extensions/extensions-store";
-import { extensionLoader } from "../../extensions/extension-loader";
+import { ExtensionsStore } from "../../extensions/extensions-store";
+import { ExtensionLoader } from "../../extensions/extension-loader";
 import { LensExtension } from "../../extensions/lens-extension";
 import { RouteHandler, RouteParams } from "../../extensions/registries/protocol-handler-registry";
 
@@ -72,7 +72,7 @@ export abstract class LensProtocolRouter extends Singleton {
 
   /**
    * find the most specific matching handler and call it
-   * @param routes the array of (path schemas, handler) paris to match against
+   * @param routes the array of (path schemas, handler) pairs to match against
    * @param url the url (in its current state)
    */
   protected _route(routes: [string, RouteHandler][], url: Url, extensionName?: string): void {
@@ -124,7 +124,7 @@ export abstract class LensProtocolRouter extends Singleton {
     const { [EXTENSION_PUBLISHER_MATCH]: publisher, [EXTENSION_NAME_MATCH]: partialName } = match.params;
     const name = [publisher, partialName].filter(Boolean).join("/");
 
-    const extension = extensionLoader.userExtensionsByName.get(name);
+    const extension = ExtensionLoader.getInstance().userExtensionsByName.get(name);
 
     if (!extension) {
       logger.info(`${LensProtocolRouter.LoggingPrefix}: Extension ${name} matched, but not installed`);
@@ -132,7 +132,7 @@ export abstract class LensProtocolRouter extends Singleton {
       return name;
     }
 
-    if (!extensionsStore.isEnabled(extension.id)) {
+    if (!ExtensionsStore.getInstance().isEnabled(extension.id)) {
       logger.info(`${LensProtocolRouter.LoggingPrefix}: Extension ${name} matched, but not enabled`);
 
       return name;

src/common/request.ts

@@ -1,12 +1,12 @@
 import request from "request";
 import requestPromise from "request-promise-native";
-import { userStore } from "./user-store";
+import { UserStore } from "./user-store";
 
 // todo: get rid of "request" (deprecated)
 // https://github.com/lensapp/lens/issues/459
 
 function getDefaultRequestOpts(): Partial<request.Options> {
-  const { httpsProxy, allowUntrustedCAs } = userStore.preferences;
+  const { httpsProxy, allowUntrustedCAs } = UserStore.getInstance().preferences;
 
   return {
     proxy: httpsProxy || undefined,

src/common/user-store.ts

@@ -38,7 +38,7 @@ export interface UserPreferences {
 export class UserStore extends BaseStore<UserStoreModel> {
   static readonly defaultTheme: ThemeId = "lens-dark";
 
-  private constructor() {
+  constructor() {
     super({
       configName: "lens-user-store",
       migrations,
@@ -163,14 +163,6 @@ export class UserStore extends BaseStore<UserStoreModel> {
     this.newContexts.clear();
   }
 
-  /**
-   * Getting default directory to download kubectl binaries
-   * @returns string
-   */
-  getDefaultKubectlPath(): string {
-    return path.join((app || remote.app).getPath("userData"), "binaries");
-  }
-
   @action
   protected async fromStore(data: Partial<UserStoreModel> = {}) {
     const { lastSeenAppVersion, seenContexts = [], preferences, kubeConfigPath } = data;
@@ -200,4 +192,10 @@ export class UserStore extends BaseStore<UserStoreModel> {
   }
 }
 
-export const userStore = UserStore.getInstance<UserStore>();
+/**
+ * Getting default directory to download kubectl binaries
+ * @returns string
+ */
+export function getDefaultKubectlPath(): string {
+  return path.join((app || remote.app).getPath("userData"), "binaries");
+}

src/common/utils/debouncePromise.ts

@@ -3,8 +3,8 @@
 export function debouncePromise<T, F extends any[]>(func: (...args: F) => T | Promise<T>, timeout = 0): (...args: F) => Promise<T> {
   let timer: NodeJS.Timeout;
 
-  return (...params: any[]) => new Promise(resolve => {
+  return (...params: F) => new Promise(resolve => {
     clearTimeout(timer);
-    timer = global.setTimeout(() => resolve(func.apply(this, params)), timeout);
+    timer = global.setTimeout(() => resolve(func(...params)), timeout);
   });
 }

src/common/utils/singleton.ts

@@ -5,25 +5,39 @@
  * @example
  *  const usersStore: UsersStore = UsersStore.getInstance();
  */
+type StaticThis<T, R extends any[]> = { new(...args: R): T };
 
-type Constructor<T = {}> = new (...args: any[]) => T;
-
-class Singleton {
+export class Singleton {
   private static instances = new WeakMap<object, Singleton>();
+  private static creating = "";
 
-  // todo: improve types inferring
-  static getInstance<T>(...args: ConstructorParameters<Constructor<T>>): T {
+  constructor() {
+    if (Singleton.creating.length === 0) {
+      throw new TypeError("A singleton class must be created by getInstanceOrCreate()");
+    }
+  }
+
+  static getInstanceOrCreate<T, R extends any[]>(this: StaticThis<T, R>, ...args: R): T {
     if (!Singleton.instances.has(this)) {
-      Singleton.instances.set(this, Reflect.construct(this, args));
+      Singleton.creating = this.name;
+      Singleton.instances.set(this, new this(...args));
+      Singleton.creating = "";
     }
 
     return Singleton.instances.get(this) as T;
   }
 
+  static getInstance<T, R extends any[]>(this: StaticThis<T, R>, strict = true): T | undefined {
+    if (!Singleton.instances.has(this) && strict) {
+      throw new TypeError(`instance of ${this.name} is not created`);
+    }
+
+    return Singleton.instances.get(this) as (T | undefined);
+  }
+
   static resetInstance() {
     Singleton.instances.delete(this);
   }
 }
 
-export { Singleton };
 export default Singleton;