add spec test

packages/firestore/src/core/sync_engine_impl.ts

@@ -1097,7 +1097,7 @@ export async function syncEngineEmitNewSnapsAndNotifyLocalStore(
  if (syncEngineImpl.isPrimaryClient) {
  // Query state is set to `current` if:
  // - The is a view change and it is up-to-date, or,
- // - There are no changes and the Target is current
+ // - We received a global snapshot and the Target is current
  const isCurrent = viewSnapshot
  ? !viewSnapshot.fromCache
  : remoteEvent?.targetChanges.get(queryView.targetId)?.current;

packages/firestore/test/unit/specs/listen_spec.test.ts

@@ -1895,4 +1895,32 @@ describeSpec('Listens:', [], () => {
  .restoreListen(query1, 'resume-token-1000', /* expectedCount= */ 1);
  }
  );
+
+ specTest(
+ 'Global snapshots would not alter query state if there is no changes',
+ ['multi-client'],
+ () => {
+ const query1 = query('collection');
+ const docA = doc('collection/a', 1000, { key: 'a' });
+ return (
+ client(0)
+ .becomeVisible()
+ // Listen to the first query in the primary client
+ .expectPrimaryState(true)
+ .userListens(query1)
+ .watchAcksFull(query1, 1000, docA)
+ .expectEvents(query1, { added: [docA] })
+ // Reproduces: https://github.com/firebase/firebase-js-sdk/issues/8314
+ // Watch could send existence filters along with a global snapshot.
+ // If existence filter matches, there will be no view changes, and query should not be
+ // marked as "not-current" as the Target is up to date.
+ .watchFilters([query1], [docA.key])
+ .watchSnapshots(2000, [], 'resume-token-2000')
+ // Listening to the query in the secondary tab. The snapshot is up to date.
+ .client(1)
+ .userListens(query1)
+ .expectEvents(query1, { added: [docA] })
+ );
+ }
+ );
 });