Fixed error TS2532 and linted the code.

tests/main.spec.ts

@@ -1,52 +1,55 @@
-import { describe, it, expect, vi, beforeEach } from 'vitest';
-import { createApp } from 'vue';
-import App from '../src/App.vue';
-import vuetify from '../src/plugins/vuetify';
-import router from '../src/router';
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { createApp } from "vue";
+import App from "~/App.vue";
+import vuetify from "~/plugins/vuetify";
+import router from "~/router";
 
-vi.mock('vue', async () => {
-  const actual = await vi.importActual('vue');
+vi.mock("vue", async () => {
+  const actual = await vi.importActual("vue");
   return {
     ...actual,
     createApp: vi.fn(),
   };
 });
 
-vi.mock('./assets/main.css', () => ({}));
+vi.mock("./assets/main.css", () => ({}));
 
-vi.mock('./plugins/vuetify', () => ({
+vi.mock("./plugins/vuetify", () => ({
   default: {
     install: vi.fn(),
   },
 }));
 
-vi.mock('./router', () => ({
+vi.mock("./router", () => ({
   default: {
     install: vi.fn(),
   },
 }));
 
-describe('main.ts', () => {
+describe("main.ts", () => {
   beforeEach(() => {
     document.body.innerHTML = '<div id="app"></div>';
-    vi.mocked(createApp).mockImplementation(() => ({
+    vi.mocked(createApp).mockImplementation(
+      () =>
+        ({
           use: vi.fn(),
           mount: vi.fn(),
-    } as any));
+        }) as any
+    );
   });
 
-  it('creates app and uses plugins', async () => {
-    await import("../src/main");
+  it("creates app and uses plugins", async () => {
+    await import("~/main");
 
     expect(createApp).toHaveBeenCalledTimes(1);
     expect(createApp).toHaveBeenCalledWith(App);
 
-    const appMock = vi.mocked(createApp).mock.results[0].value;
+    const appMock = vi.mocked(createApp).mock.results[0]?.value;
     expect(appMock.use).toHaveBeenCalledTimes(2);
     expect(appMock.use).toHaveBeenCalledWith(vuetify);
     expect(appMock.use).toHaveBeenCalledWith(router);
 
     expect(appMock.mount).toHaveBeenCalledTimes(1);
-    expect(appMock.mount).toHaveBeenCalledWith('#app');
+    expect(appMock.mount).toHaveBeenCalledWith("#app");
   });
 });