Mock next-auth session for client tests

frontend/jest.setup.ts

@@ -1,4 +1,5 @@
 import '@testing-library/jest-dom'
+import { Session } from 'next-auth'
 
 Element.prototype.scrollIntoView = () => {}
 
@@ -15,3 +16,32 @@ Object.defineProperty(window, 'matchMedia', {
     dispatchEvent: jest.fn()
   }))
 })
+
+// **Global Mocks**
+
+// Due to Jest transformer issues, we mock next-auth's  getServerSession and the authOptions directly:
+export const mockSession: Session = {
+  expires: new Date(Date.now() + 2 * 86400).toISOString(),
+  user: {
+    name: 'user',
+    id: 0,
+    username: 'username',
+    email: '[email protected]',
+    firstName: 'user',
+    lastName: 'last name',
+    capacities: [],
+    roles: ['staff', 'admin'],
+    authorizedScopes: ['client:read']
+  }
+}
+
+jest.mock('./src/app/api/auth/[...nextauth]/route', () => {
+  return { authOptions: () => {} }
+})
+
+jest.mock('next-auth', () => {
+  return {
+    __esModule: true,
+    getServerSession: jest.fn(() => Promise.resolve(mockSession))
+  }
+})