Feature/unit tests (#184)

core/test/mockLocalStorage.ts

@@ -0,0 +1,22 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
+const mockLocalStorage = (function () {
+  let store: Record<string, any> = {};
+  return {
+    getItem(key: string) {
+      return store[key] ?? null;
+    },
+    setItem(key: string, value: any) {
+      store[key] = value.toString();
+    },
+    clear() {
+      store = {};
+    },
+    removeItem(key: string) {
+      delete store[key];
+    },
+  };
+})();
+
+Object.defineProperty(window, 'localStorage', { value: mockLocalStorage });
+
+export {};