fix: correct fetch mocking in group-sync tests

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

@@ -2,8 +2,9 @@ import { describe, it, expect, beforeEach, mock, spyOn } from 'bun:test';
 import { GroupSyncService } from '../../../src/services/group-sync';
 import { db } from '../../../src/db';
 
-// Mock process.env for testing
+// Store original globals
 const originalEnv = { ...process.env };
+const originalFetch = globalThis.fetch;
 process.env = {
   WHATSAPP_COMMUNITY_ID: 'test-community',
   EVOLUTION_API_URL: 'http://test-api',
@@ -13,7 +14,7 @@ process.env = {
 };
 
 // Mock fetch
-const mockFetch = mock.global('fetch', async () => ({
+const fetchMock = mock(async () => ({
   ok: true,
   json: async () => [
     { id: 'group1', subject: 'Group 1', linkedParent: 'test-community' },
@@ -22,6 +23,9 @@ const mockFetch = mock.global('fetch', async () => ({
   ]
 }));
 
+// Replace global fetch
+globalThis.fetch = fetchMock;
+
 describe('GroupSyncService', () => {
   beforeEach(() => {
     db.exec('DELETE FROM groups');
@@ -31,7 +35,7 @@ describe('GroupSyncService', () => {
 
   afterAll(() => {
     process.env = originalEnv;
-    mockFetch.mockRestore();
+    globalThis.fetch = originalFetch;
   });
 
   describe('syncGroups', () => {