test: add unit and acceptance tests for auth, permissions, Elo, and home page

src/__tests__/auth-simple.test.ts

@@ -0,0 +1,53 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { getSession } from '@/lib/auth-simple'
+
+// Mock next/headers
+vi.mock('next/headers', () => ({
+  cookies: vi.fn().mockResolvedValue({
+    get: vi.fn().mockReturnValue({ name: 'better-auth.session_token', value: 'test-token' }),
+  }),
+}))
+
+// Mock fetch
+const mockFetch = vi.fn()
+global.fetch = mockFetch as any
+
+describe('getSession', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  it('returns session data when auth API returns 200', async () => {
+    const mockSession = {
+      session: { token: 'test-token', expiresAt: new Date().toISOString() },
+      user: { id: 'user-123', email: 'test@example.com' },
+    }
+
+    mockFetch.mockResolvedValue(
+      new Response(JSON.stringify(mockSession), { status: 200 })
+    )
+
+    const result = await getSession()
+
+    expect(result).toEqual(mockSession)
+    expect(mockFetch).toHaveBeenCalled()
+  })
+
+  it('returns null when auth API returns non-200 status', async () => {
+    mockFetch.mockResolvedValue(
+      new Response(null, { status: 401 })
+    )
+
+    const result = await getSession()
+
+    expect(result).toBeNull()
+  })
+
+  it('returns null when an error occurs', async () => {
+    mockFetch.mockRejectedValue(new Error('Network error'))
+
+    const result = await getSession()
+
+    expect(result).toBeNull()
+  })
+})