fix(tests): mock useAuth in Layout tests for auth-aware navigation

Layout now renders different nav links based on auth state. Tests were
using a real AuthProvider which resolved to no user, causing them to
look for "My Runs" and "Admin" links that only appear when logged in.

Mock useAuth to test both logged-out and logged-in-as-admin states.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/components/Layout.test.tsx

@@ -2,62 +2,108 @@ import { render, screen } from '@testing-library/react'
 import userEvent from '@testing-library/user-event'
 import { MemoryRouter } from 'react-router-dom'
 import { Layout } from './Layout'
-import { AuthProvider } from '../contexts/AuthContext'
 
 vi.mock('../hooks/useTheme', () => ({
   useTheme: () => ({ theme: 'dark' as const, toggle: vi.fn() }),
 }))
 
+const mockUseAuth = vi.fn()
+vi.mock('../contexts/AuthContext', () => ({
+  useAuth: () => mockUseAuth(),
+}))
+
+const loggedOutAuth = {
+  user: null,
+  session: null,
+  loading: false,
+  isAdmin: false,
+  signInWithEmail: vi.fn(),
+  signUpWithEmail: vi.fn(),
+  signInWithGoogle: vi.fn(),
+  signInWithDiscord: vi.fn(),
+  signOut: vi.fn(),
+}
+
+const adminAuth = {
+  ...loggedOutAuth,
+  user: { email: 'admin@example.com' },
+  session: {},
+  isAdmin: true,
+}
+
 function renderLayout(initialPath = '/') {
   return render(
     <MemoryRouter initialEntries={[initialPath]}>
-      <AuthProvider>
-        <Layout />
-      </AuthProvider>
+      <Layout />
     </MemoryRouter>
   )
 }
 
 describe('Layout', () => {
-  it('renders all desktop navigation links', () => {
-    renderLayout()
-    expect(screen.getAllByRole('link', { name: /new run/i })[0]).toBeInTheDocument()
-    expect(screen.getAllByRole('link', { name: /my runs/i })[0]).toBeInTheDocument()
-    expect(screen.getAllByRole('link', { name: /genlockes/i })[0]).toBeInTheDocument()
-    expect(screen.getAllByRole('link', { name: /stats/i })[0]).toBeInTheDocument()
-    expect(screen.getAllByRole('link', { name: /admin/i })[0]).toBeInTheDocument()
+  describe('when logged out', () => {
+    beforeEach(() => mockUseAuth.mockReturnValue(loggedOutAuth))
+
+    it('renders logged-out navigation links', () => {
+      renderLayout()
+      expect(screen.getAllByRole('link', { name: /^home$/i })[0]).toBeInTheDocument()
+      expect(screen.getAllByRole('link', { name: /^runs$/i })[0]).toBeInTheDocument()
+      expect(screen.getAllByRole('link', { name: /genlockes/i })[0]).toBeInTheDocument()
+      expect(screen.getAllByRole('link', { name: /stats/i })[0]).toBeInTheDocument()
+    })
+
+    it('does not show authenticated links', () => {
+      renderLayout()
+      expect(screen.queryByRole('link', { name: /new run/i })).not.toBeInTheDocument()
+      expect(screen.queryByRole('link', { name: /my runs/i })).not.toBeInTheDocument()
+      expect(screen.queryByRole('link', { name: /admin/i })).not.toBeInTheDocument()
+    })
+
+    it('shows sign-in link', () => {
+      renderLayout()
+      expect(screen.getByRole('link', { name: /sign in/i })).toBeInTheDocument()
+    })
+  })
+
+  describe('when logged in as admin', () => {
+    beforeEach(() => mockUseAuth.mockReturnValue(adminAuth))
+
+    it('renders authenticated navigation links', () => {
+      renderLayout()
+      expect(screen.getAllByRole('link', { name: /new run/i })[0]).toBeInTheDocument()
+      expect(screen.getAllByRole('link', { name: /my runs/i })[0]).toBeInTheDocument()
+      expect(screen.getAllByRole('link', { name: /genlockes/i })[0]).toBeInTheDocument()
+      expect(screen.getAllByRole('link', { name: /stats/i })[0]).toBeInTheDocument()
+      expect(screen.getAllByRole('link', { name: /admin/i })[0]).toBeInTheDocument()
+    })
+
+    it('shows the mobile dropdown when the hamburger is clicked', async () => {
+      renderLayout()
+      const hamburger = screen.getByRole('button', { name: /toggle menu/i })
+      await userEvent.click(hamburger)
+      expect(screen.getAllByRole('link', { name: /my runs/i }).length).toBeGreaterThan(1)
+    })
   })
 
   it('renders the brand logo link', () => {
+    mockUseAuth.mockReturnValue(loggedOutAuth)
     renderLayout()
     expect(screen.getByRole('link', { name: /ant/i })).toBeInTheDocument()
   })
 
   it('renders the theme toggle button', () => {
+    mockUseAuth.mockReturnValue(loggedOutAuth)
     renderLayout()
     expect(screen.getAllByRole('button', { name: /switch to light mode/i })[0]).toBeInTheDocument()
   })
 
   it('initially hides the mobile dropdown menu', () => {
+    mockUseAuth.mockReturnValue(loggedOutAuth)
     renderLayout()
-    // Mobile menu items exist in DOM but menu is hidden; the mobile dropdown
-    // only appears inside the sm:hidden block after state toggle.
-    // The hamburger button should be present.
     expect(screen.getByRole('button', { name: /toggle menu/i })).toBeInTheDocument()
   })
 
-  it('shows the mobile dropdown when the hamburger is clicked', async () => {
-    renderLayout()
-    const hamburger = screen.getByRole('button', { name: /toggle menu/i })
-    await userEvent.click(hamburger)
-    // After click, the menu open state adds a dropdown with nav links
-    // We can verify the menu is open by checking a class change or that
-    // the nav links appear in the mobile dropdown section.
-    // The mobile dropdown renders navLinks in a div inside sm:hidden
-    expect(screen.getAllByRole('link', { name: /my runs/i }).length).toBeGreaterThan(1)
-  })
-
   it('renders the footer with PokeDB attribution', () => {
+    mockUseAuth.mockReturnValue(loggedOutAuth)
     renderLayout()
     expect(screen.getByRole('link', { name: /pokedb/i })).toBeInTheDocument()
   })