Introduce a legacy-helper to make gradual refactoring of inheritors of Singleton easier

Signed-off-by: Iku-turso <mikko.aspiala@gmail.com>

src/extensions/as-legacy-globals-for-extension-api/as-legacy-global-singleton-object-for-extension-api.ts

@@ -0,0 +1,36 @@
+/**
+ * Copyright (c) OpenLens Authors. All rights reserved.
+ * Licensed under MIT License. See LICENSE in root directory for more information.
+ */
+import type { Injectable } from "@ogre-tools/injectable";
+import { asLegacyGlobalForExtensionApi } from "./as-legacy-global-object-for-extension-api";
+import { getLegacyGlobalDiForExtensionApi } from "./legacy-global-di-for-extension-api";
+import loggerInjectable from "../../common/logger.injectable";
+
+export const asLegacyGlobalSingletonForExtensionApi = <
+  Instance,
+  InstantiationParameter = void,
+>(
+    injectable: Injectable<Instance, unknown, InstantiationParameter>,
+    instantiationParameter?: InstantiationParameter,
+  ) => {
+  const instance = asLegacyGlobalForExtensionApi(
+    injectable,
+    instantiationParameter,
+  );
+
+  return {
+    createInstance: () => instance,
+
+    getInstance: () => instance,
+
+    resetInstance: () => {
+      const di = getLegacyGlobalDiForExtensionApi();
+      const logger = di.inject(loggerInjectable);
+
+      logger.warn(
+        `resetInstance() for a legacy global singleton of "${injectable.id}" does nothing.`,
+      );
+    },
+  };
+};