fix: correct test setup and cleanup in group-sync tests

tests/unit/services/group-sync.test.ts

@@ -1,4 +1,4 @@
-import { describe, it, expect, beforeEach, mock, spyOn } from 'bun:test';
+import { describe, it, expect, beforeEach, afterAll, mock } from 'bun:test';
 import { GroupSyncService } from '../../../src/services/group-sync';
 import { db } from '../../../src/db';
 
@@ -30,11 +30,20 @@ describe('GroupSyncService', () => {
   beforeEach(() => {
     db.exec('DELETE FROM groups');
     GroupSyncService['lastSyncAttempt'] = 0;
-    Object.assign(env, mockEnv);
+    // Reset process.env to mock values
+    process.env.WHATSAPP_COMMUNITY_ID = 'test-community';
+    process.env.EVOLUTION_API_URL = 'http://test-api';
+    process.env.EVOLUTION_API_INSTANCE = 'test-instance';
+    process.env.EVOLUTION_API_KEY = 'test-key';
   });
 
   afterAll(() => {
-    process.env = originalEnv;
+    // Restore original process.env
+    process.env.WHATSAPP_COMMUNITY_ID = originalEnv.WHATSAPP_COMMUNITY_ID;
+    process.env.EVOLUTION_API_URL = originalEnv.EVOLUTION_API_URL;
+    process.env.EVOLUTION_API_INSTANCE = originalEnv.EVOLUTION_API_INSTANCE;
+    process.env.EVOLUTION_API_KEY = originalEnv.EVOLUTION_API_KEY;
+    // Restore original fetch
     globalThis.fetch = originalFetch;
   });
 
@@ -88,7 +97,10 @@ describe('GroupSyncService', () => {
     });
 
     it('should handle API errors', async () => {
-      mockFetch.mockImplementationOnce(() => Promise.resolve({ ok: false, statusText: 'Not Found' }));
+      globalThis.fetch = mock(async () => ({
+        ok: false,
+        statusText: 'Not Found'
+      }));
       await expect(GroupSyncService.syncGroups()).rejects.toThrow('API request failed: Not Found');
     });
   });