feat: exponer group_sync_seconds_until_next y adaptar tests

Co-authored-by: aider (openrouter/openai/gpt-5) <aider@aider.chat>

src/server.ts

@@ -84,6 +84,12 @@ export class WebhookServer {
 				Metrics.set('allowed_groups_total_allowed', allowed);
 				Metrics.set('allowed_groups_total_blocked', blocked);
 			} catch {}
+			// Exponer métrica con el tiempo restante hasta el próximo group sync (o -1 si scheduler inactivo)
+			try {
+				const secs = GroupSyncService.getSecondsUntilNextGroupSync();
+				const val = (secs == null || !Number.isFinite(secs)) ? -1 : secs;
+				Metrics.set('group_sync_seconds_until_next', val);
+			} catch {}
 			const format = (process.env.METRICS_FORMAT || 'prom').toLowerCase() === 'json' ? 'json' : 'prom';
 			const body = Metrics.render(format as any);
 			return new Response(body, {

src/services/group-sync.ts

@@ -71,6 +71,8 @@ export class GroupSyncService {
 	private static _groupsSchedulerRunning = false;
 	private static _membersTimer: any = null;
 	private static _membersSchedulerRunning = false;
+	private static _groupsIntervalMs: number | null = null;
+	private static _groupsNextTickAt: number | null = null;
 
 	static async syncGroups(force: boolean = false): Promise<{ added: number; updated: number }> {
 		if (!this.shouldSync(force)) {
@@ -682,8 +684,12 @@ export class GroupSyncService {
 		if (process.env.NODE_ENV === 'development' && interval < 10000) {
 			interval = 10000;
 		}
+		this._groupsIntervalMs = interval;
+		this._groupsNextTickAt = Date.now() + interval;
 
 		this._groupsTimer = setInterval(() => {
+			// Programar el siguiente tick antes de ejecutar la sincronización
+			this._groupsNextTickAt = Date.now() + (this._groupsIntervalMs ?? interval);
 			this.syncGroups().catch(err => {
 				console.error('❌ Groups scheduler run error:', err);
 			});
@@ -696,6 +702,15 @@ export class GroupSyncService {
 			clearInterval(this._groupsTimer);
 			this._groupsTimer = null;
 		}
+		this._groupsIntervalMs = null;
+		this._groupsNextTickAt = null;
+	}
+
+	public static getSecondsUntilNextGroupSync(nowMs: number = Date.now()): number | null {
+		const next = this._groupsNextTickAt;
+		if (next == null) return null;
+		const secs = (next - nowMs) / 1000;
+		return secs > 0 ? secs : 0;
 	}
 
 	public static startMembersScheduler(): void {

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

@@ -3,6 +3,7 @@ import { GroupSyncService } from '../../../src/services/group-sync';
 
 const envBackup = { ...process.env };
 let originalSyncMembers: any;
+let originalSyncGroups: any;
 
 function sleep(ms: number) {
   return new Promise(res => setTimeout(res, ms));
@@ -11,11 +12,14 @@ function sleep(ms: number) {
 describe('GroupSyncService - scheduler de miembros', () => {
   beforeEach(() => {
     originalSyncMembers = GroupSyncService.syncMembersForActiveGroups;
+    originalSyncGroups = GroupSyncService.syncGroups;
   });
 
   afterEach(() => {
     GroupSyncService.stopMembersScheduler();
+    GroupSyncService.stopGroupsScheduler();
     GroupSyncService.syncMembersForActiveGroups = originalSyncMembers;
+    GroupSyncService.syncGroups = originalSyncGroups;
     process.env = envBackup;
   });
 
@@ -45,4 +49,36 @@ describe('GroupSyncService - scheduler de miembros', () => {
     GroupSyncService.stopMembersScheduler();
     expect(called).toBeGreaterThanOrEqual(1);
   });
+
+  test('groups scheduler no arranca en entorno de test', async () => {
+    process.env = { ...envBackup, NODE_ENV: 'test' };
+    let called = 0;
+    GroupSyncService.syncGroups = async () => {
+      called++;
+      return { added: 0, updated: 0 };
+    };
+
+    GroupSyncService.startGroupsScheduler();
+    await sleep(100);
+    expect(called).toBe(0);
+    expect(GroupSyncService.getSecondsUntilNextGroupSync()).toBeNull();
+  });
+
+  test('groups scheduler arranca en producción y programa next tick', async () => {
+    process.env = { ...envBackup, NODE_ENV: 'production', GROUP_SYNC_INTERVAL_MS: '30' };
+    let called = 0;
+    GroupSyncService.syncGroups = async () => {
+      called++;
+      return { added: 0, updated: 0 };
+    };
+
+    GroupSyncService.startGroupsScheduler();
+    const secs1 = GroupSyncService.getSecondsUntilNextGroupSync();
+    expect(secs1).not.toBeNull();
+    expect(Number(secs1)).toBeGreaterThan(0);
+
+    await sleep(120);
+    GroupSyncService.stopGroupsScheduler();
+    expect(called).toBeGreaterThanOrEqual(1);
+  });
 });

tests/unit/services/metrics-health.test.ts

@@ -37,6 +37,7 @@ describe('/metrics y /health (detallado)', () => {
     expect(body).toContain('last_sync_ok');
     expect(body).toContain('active_groups 2');
     expect(body).toContain('webhook_events_total_messages_upsert 3');
+    expect(body).toContain('group_sync_seconds_until_next');
   });
 
   test('/health?full=1 devuelve JSON con contadores y snapshot', async () => {