test(frontend): navigation works correctly

Signed-off-by: Márk Kővári <kovarimarkofficial@gmail.com>

frontend/src/App.test.tsx

@@ -0,0 +1,46 @@
+import { render } from '@testing-library/react';
+import { describe, it, expect } from 'vitest';
+import { App } from './App';
+import { act } from 'react';
+
+
+describe('App', () => {
+    it('should render successfully', () => {
+        render(<App />);
+        expect(true).toBe(true);
+    });
+
+    it('should render the main page', () => {
+        const { getByRole } = render(<App />);
+        expect(getByRole('heading', { name: /Home/i })).toBeInTheDocument();
+    });
+
+    it('should render the login page after clicked on the login link', () => {
+        const { getByRole } = render(<App />);
+
+        act(() => {
+            getByRole('link', { name: /login/i }).click();
+        });
+        expect(getByRole('heading', { name: /login/i })).toBeInTheDocument();
+    });
+
+    it('should render the main page after visited the register page and clicked on the home link', () => {
+        const { getByRole } = render(<App />);
+
+        act(() => {
+            getByRole('link', { name: /main/i }).click();
+        });
+        expect(getByRole('heading', { name: /home/i })).toBeInTheDocument();
+    });
+
+
+    it('should render the register page after clicked on the register link', () => {
+        const { getByRole } = render(<App />);
+
+        act(() => {
+            getByRole('link', { name: /register/i }).click();
+        });
+        expect(getByRole('heading', { name: /register/i })).toBeInTheDocument();
+    });
+
+});