check client offline state and test (#6579)

Author: milaGGL

packages/firestore/src/core/firestore_client.ts

@@ -40,6 +40,7 @@ import { toByteStreamReader } from '../platform/byte_stream_reader';
 import { newSerializer, newTextEncoder } from '../platform/serializer';
 import { Datastore } from '../remote/datastore';
 import {
+  canUseNetwork,
   RemoteStore,
   remoteStoreDisableNetwork,
   remoteStoreEnableNetwork,
@@ -507,9 +508,26 @@ export function firestoreClientRunAggregationQuery(
   client: FirestoreClient,
   query: AggregateQuery
 ): Promise<AggregateQuerySnapshot> {
-  return client.asyncQueue.enqueue(() => {
-    return getAggregate(query);
+  const deferred = new Deferred<AggregateQuerySnapshot>();
+  client.asyncQueue.enqueueAndForget(async () => {
+    const remoteStore = await getRemoteStore(client);
+    if (!canUseNetwork(remoteStore)) {
+      deferred.reject(
+        new FirestoreError(
+          Code.UNAVAILABLE,
+          'Failed to get aggregate result because the client is offline.'
+        )
+      );
+    } else {
+      try {
+        const result = await getAggregate(query);
+        deferred.resolve(result);
+      } catch (e) {
+        deferred.reject(e as Error);
+      }
+    }
   });
+  return deferred.promise;
 }
 
 async function readDocumentFromCache(

packages/firestore/test/integration/api/aggregation.test.ts

@@ -19,6 +19,7 @@ import { expect } from 'chai';
 
 import {
   countQuery,
+  disableNetwork,
   getAggregateFromServerDirect,
   query
 } from '../util/firebase_export';
@@ -38,4 +39,21 @@ apiDescribe('Aggregation query', (persistence: boolean) => {
       expect(snapshot.getCount()).to.equal(3);
     });
   });
+
+  it('getAggregateFromServerDirect fails if user is offline', () => {
+    const testDocs = {};
+    return withTestCollection(
+      persistence,
+      testDocs,
+      async (collection, firestore) => {
+        await disableNetwork(firestore);
+        const countQuery_ = countQuery(collection);
+        await expect(
+          getAggregateFromServerDirect(countQuery_)
+        ).to.be.eventually.rejectedWith(
+          'Failed to get aggregate result because the client is offline'
+        );
+      }
+    );
+  });
 });