updated nextOffset calculation for hereNow to consider currently fetched users count

Author: Mohit Tejani

pubnub/lib/src/dx/_endpoints/presence.dart

@@ -356,21 +356,26 @@ class HereNowResult extends Result {
       var channelsOccupancies = (payload['channels'] as Map<String, dynamic>)
           .map((key, value) => MapEntry(key,
               ChannelOccupancy.fromJson(key, value as Map<String, dynamic>)));
-      var maxOccupancy = channelsOccupancies.values
-          .map((channel) => channel.count)
-          .reduce((a, b) => a > b ? a : b);
-      if ((offset! + limit!) < maxOccupancy) {
-        nextOffset = offset + limit;
+      var maxOccupancyChannel = channelsOccupancies.values
+          .reduce((a, b) => a.count > b.count ? a : b);
+
+      if ((offset! + maxOccupancyChannel.uuids.length) <
+          maxOccupancyChannel.count) {
+        nextOffset = offset + maxOccupancyChannel.uuids.length;
       }
       return HereNowResult._(channelsOccupancies,
           payload['total_occupancy'] as int, payload['total_channels'] as int,
           nextOffset: nextOffset);
     } else {
-      if (result.otherKeys['occupancy'] as int > (limit! + offset!)) {
-        nextOffset = limit + offset;
+      var channelOccupancy =
+          ChannelOccupancy.fromJson(channelName!, result.otherKeys);
+      var fetchedOccupanciesCount = channelOccupancy.uuids.length;
+      if (result.otherKeys['occupancy'] as int >
+          (fetchedOccupanciesCount + offset!)) {
+        nextOffset = fetchedOccupanciesCount + offset;
       }
       return HereNowResult._({
-        channelName: ChannelOccupancy.fromJson(channelName!, result.otherKeys)
+        channelName: channelOccupancy
       }, result.otherKeys['occupancy'] as int, 1, nextOffset: nextOffset);
     }
   }

pubnub/test/integration/channel_groups/channel_groups_test.dart

@@ -256,20 +256,22 @@ void main() {
 
       // 2. Subscribe to Group - Create subscription to channel group
       var subscription = pubnub!.subscribe(channelGroups: {groupName});
-      
+
       // Wait for subscription to actually start listening
       await subscription.whenStarts;
-      await Future.delayed(Duration(seconds: 2)); // Additional buffer for subscription to be fully ready
+      await Future.delayed(Duration(
+          seconds: 2)); // Additional buffer for subscription to be fully ready
 
       // 3. Setup Message Listener - Set up listener BEFORE publishing
       var messageReceived = false;
       var messageCompleter = Completer<void>();
       var testMessage = 'Hello from channel group integration test!';
 
       var testChannel = 'test_ch1_$randomSuffix';
-      
+
       subscription.messages.listen((envelope) {
-        if (envelope.payload == testMessage && envelope.channel == testChannel) {
+        if (envelope.payload == testMessage &&
+            envelope.channel == testChannel) {
           messageReceived = true;
           if (!messageCompleter.isCompleted) {
             messageCompleter.complete();
@@ -286,18 +288,24 @@ void main() {
       } catch (e) {
         // Timeout occurred
       }
-      
+
       expect(messageReceived, isTrue,
           reason:
               'Message should be received through channel group subscription');
 
       // 5. Group Modification - Add/remove channels and verify subscription updates
-      await pubnub!.channelGroups.addChannels(groupName, {'test_ch3_$randomSuffix'});
+      await pubnub!.channelGroups
+          .addChannels(groupName, {'test_ch3_$randomSuffix'});
       await waitForConsistency();
 
       var listResult = await pubnub!.channelGroups.listChannels(groupName);
-      expect(listResult.channels,
-          containsAll({'test_ch1_$randomSuffix', 'test_ch2_$randomSuffix', 'test_ch3_$randomSuffix'}));
+      expect(
+          listResult.channels,
+          containsAll({
+            'test_ch1_$randomSuffix',
+            'test_ch2_$randomSuffix',
+            'test_ch3_$randomSuffix'
+          }));
 
       await subscription.cancel();
     }, timeout: Timeout(Duration(seconds: 45)));

pubnub/test/unit/dx/fixtures/presence.dart

@@ -170,7 +170,7 @@ const _hereNowMixedStateResponse = '''
 }
 ''';
 
-const _hereNowWithOutNextOffsetResponse = '''
+const _hereNowWithNextOffsetNeededResponse = '''
 {
   "message": "OK",
   "payload": {

pubnub/test/unit/dx/presence_test.dart

@@ -224,12 +224,12 @@ void main() {
           method: 'GET',
           path:
               '/v2/presence/sub_key/demo/channel/test,my_channel?uuid=test&disable_uuids=0&limit=1000',
-        ).then(status: 200, body: _hereNowWithOutNextOffsetResponse);
+        ).then(status: 200, body: _hereNowWithNextOffsetNeededResponse);
 
         final hereNowResponse = await pubnub!.hereNow(
           channels: {'test', 'my_channel'},
         );
-        expect(hereNowResponse.nextOffset, equals(null));
+        expect(hereNowResponse.nextOffset, equals(3));
       });
     });