test: added test to ErrorHandling

frontend/src/__test__/screens/ErrorHandling.test.tsx

@@ -0,0 +1,83 @@
+import React from 'react';
+import { render } from '@testing-library/react';
+import { MemoryRouter, Navigate } from 'react-router-dom';
+import { describe, it, expect, vi } from 'vitest';
+import ErrorHandling from '../../screens/ErrorHandling';
+import { useRouteError, isRouteErrorResponse } from 'react-router-dom';
+
+vi.mock('react-router-dom', async () => {
+  const actual = await vi.importActual('react-router-dom');
+  return {
+    ...actual,
+    useRouteError: vi.fn(),
+    isRouteErrorResponse: vi.fn(),
+    Navigate: vi.fn(({ to, replace }) => <div>Navigate to {to} - {replace}</div>),
+  };
+});
+
+describe('ErrorHandling', () => {
+  it('should navigate to / when error status is 401', () => {
+    (useRouteError as vi.Mock).mockReturnValue({ status: 401 });
+    (isRouteErrorResponse as vi.Mock).mockReturnValue(true);
+
+    const { getByText } = render(
+      <MemoryRouter>
+        <ErrorHandling />
+      </MemoryRouter>
+    );
+
+    expect(getByText('Navigate to / -')).toBeDefined();
+  });
+
+  it('should display Unauthorized when error status is 403', () => {
+    (useRouteError as vi.Mock).mockReturnValue({ status: 403 });
+    (isRouteErrorResponse as vi.Mock).mockReturnValue(true);
+
+    const { getByText } = render(
+      <MemoryRouter>
+        <ErrorHandling />
+      </MemoryRouter>
+    );
+
+    expect(getByText('Unauthorized')).toBeDefined();
+  });
+
+  it('should display Page Not Found when error status is 404', () => {
+    (useRouteError as vi.Mock).mockReturnValue({ status: 404 });
+    (isRouteErrorResponse as vi.Mock).mockReturnValue(true);
+
+    const { getByText } = render(
+      <MemoryRouter>
+        <ErrorHandling />
+      </MemoryRouter>
+    );
+
+    expect(getByText('Page Not Found')).toBeDefined();
+  });
+
+  it('should display default error message for other types of errors', () => {
+    (useRouteError as vi.Mock).mockReturnValue({ status: 500 });
+    (isRouteErrorResponse as vi.Mock).mockReturnValue(true);
+
+    const { getByText } = render(
+      <MemoryRouter>
+        <ErrorHandling />
+      </MemoryRouter>
+    );
+
+    expect(getByText('Oops! Something went wrong')).toBeDefined();
+  });
+
+  it('should display default error message when error is not a route error response', () => {
+    (useRouteError as vi.Mock).mockReturnValue(new Error('Test error'));
+    (isRouteErrorResponse as vi.Mock).mockReturnValue(false);
+
+    const { getByText } = render(
+      <MemoryRouter>
+        <ErrorHandling />
+      </MemoryRouter>
+    );
+
+    expect(getByText('Oops! Something went wrong')).toBeDefined();
+  });
+});