Create logout route (#48)

* Add logout route

* Add tests for logout route

* Fix failing tests

backend/app/api/user/logout/auth.test.ts

@@ -0,0 +1,16 @@
+import { GET } from './route';
+
+jest.mock('@/lib/session', () => ({
+  verifySession: jest.fn(() => ({
+    isAuth: true,
+    uid: 3,
+  })),
+  deleteSession: jest.fn(() => {}),
+}));
+
+test('Logout succeeds for valid session', async () => {
+  const res = await GET();
+  const data = await res.json();
+
+  expect(data.success).toBeTruthy();
+});

backend/app/api/user/logout/noAuth.test.ts

@@ -0,0 +1,15 @@
+import { GET } from './route';
+
+jest.mock('@/lib/session', () => ({
+  verifySession: jest.fn(() => ({
+    isAuth: false,
+  })),
+  deleteSession: jest.fn(() => {}),
+}));
+
+test('Logout fails for invalid session', async () => {
+  const res = await GET();
+  const data = await res.json();
+
+  expect(data.error).toEqual('User not authenticated');
+});

backend/app/api/user/logout/route.ts

@@ -0,0 +1,20 @@
+import { deleteSession, verifySession } from '@/lib/session';
+import { NextResponse } from 'next/server';
+
+type GetResponse = {
+  success: boolean;
+};
+
+export const GET = async (): Promise<
+  NextResponse<GetResponse | { error: string }>
+> => {
+  const currentSession = await verifySession();
+
+  if (!currentSession.isAuth) {
+    return NextResponse.json({ error: 'User not authenticated' });
+  }
+
+  await deleteSession();
+
+  return NextResponse.json({ success: true });
+};