fix(xtream): prevent stale epg queue fetches

libs/portal/xtream/data-access/src/lib/services/epg-queue.service.spec.ts

@@ -33,7 +33,7 @@ describe('EpgQueueService', () => {
     beforeEach(() => {
         jest.useFakeTimers();
 
-        xtreamApi = { getShortEpg: jest.fn() };
+        xtreamApi = { getShortEpg: jest.fn().mockResolvedValue([]) };
         fallback = {
             getProgramsForChannel: jest.fn().mockResolvedValue([]),
             getCurrentProgramsBatch: jest.fn().mockResolvedValue({}),
@@ -165,8 +165,8 @@ describe('EpgQueueService', () => {
 
     it('only the latest enqueue commits queue state when prefetches overlap', async () => {
         // Defer batch resolutions so we can interleave them.
-        let resolveA: (v: Record<string, EpgItem>) => void = () => {};
-        let resolveB: (v: Record<string, EpgItem>) => void = () => {};
+        let resolveA!: (v: Record<string, EpgItem>) => void;
+        let resolveB!: (v: Record<string, EpgItem>) => void;
         fallback.getCurrentProgramsBatch
             .mockImplementationOnce(
                 () =>
@@ -229,6 +229,44 @@ describe('EpgQueueService', () => {
         sub.unsubscribe();
     });
 
+    it('drops stale queued provider fetches while a newer XMLTV prefetch is pending', async () => {
+        let resolveLatestBatch!: (v: Record<string, EpgItem>) => void;
+        fallback.getCurrentProgramsBatch.mockImplementationOnce(
+            () =>
+                new Promise<Record<string, EpgItem>>((resolve) => {
+                    resolveLatestBatch = resolve;
+                })
+        );
+        xtreamApi.getShortEpg.mockResolvedValue([]);
+
+        await service.enqueue([1, 2], new Set([1, 2]), credentials);
+        expect(xtreamApi.getShortEpg).toHaveBeenCalledWith(
+            credentials,
+            1,
+            3,
+            { suppressErrorLog: true }
+        );
+
+        const latestEnqueue = service.enqueue(
+            [{ streamId: 3, epgChannelId: 'three.epg' }],
+            new Set([3]),
+            credentials
+        );
+
+        jest.advanceTimersByTime(201);
+        await Promise.resolve();
+
+        expect(xtreamApi.getShortEpg).not.toHaveBeenCalledWith(
+            credentials,
+            2,
+            3,
+            { suppressErrorLog: true }
+        );
+
+        resolveLatestBatch({});
+        await latestEnqueue;
+    });
+
     it('clones the caller visibleIds Set so external mutation is harmless', async () => {
         const visible = new Set([1, 2, 3]);
         await service.enqueue(

libs/portal/xtream/data-access/src/lib/services/epg-queue.service.ts

@@ -123,6 +123,12 @@ export class EpgQueueService implements OnDestroy {
             streamsByEpgId.set(id, list);
         }
 
+        // Make the latest viewport visible to any currently running queue
+        // before the async XMLTV prefetch returns, so stale queued provider
+        // requests are dropped immediately on fast scroll.
+        this.visibleSet = new Set(visibleIds);
+        this.queue = [];
+
         const batchResult = await this.fetchXmltvCurrentPure(
             Array.from(streamsByEpgId.keys())
         );
@@ -130,8 +136,6 @@ export class EpgQueueService implements OnDestroy {
         if (generation !== this.enqueueGeneration) return;
 
         // Atomic commit block — no awaits below.
-        // Clone the caller's Set so external mutation cannot shift our state.
-        this.visibleSet = new Set(visibleIds);
         this.pruneEphemeralMaps(this.visibleSet);
 
         for (const entry of normalized) {

libs/portal/xtream/data-access/src/lib/stores/features/with-epg.feature.spec.ts

@@ -63,24 +63,8 @@ function configureStore(setup: TestStoreSetup) {
 
     const fallbackService = {
         getProgramsForChannel: jest.fn<Promise<EpgItem[]>, unknown[]>(),
-        resolveCurrentEpg: jest.fn(
-            async (args: {
-                epgChannelId: string | null | undefined;
-                preferUploaded: boolean;
-                fetchProvider: () => Promise<EpgItem[]>;
-            }): Promise<EpgItem[]> => {
-                const id = (args.epgChannelId ?? '').trim();
-                if (args.preferUploaded && id) {
-                    const xmltv =
-                        await fallbackService.getProgramsForChannel(id);
-                    if (xmltv.length > 0) return xmltv;
-                    return args.fetchProvider();
-                }
-                const provider = await args.fetchProvider();
-                if (provider.length > 0 || !id) return provider;
-                return fallbackService.getProgramsForChannel(id);
-            }
-        ),
+        resolveCurrentEpg:
+            XtreamXmltvFallbackService.prototype.resolveCurrentEpg,
     };
 
     const settingsStore = {