handling invalid presence event data in subscription

pubnub · Apr 15, 2024 · 45e793e · 45e793e
1 parent 40b6bb6
commit 45e793e
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Showing 2 changed files with 22 additions and 4 deletions.
diff --git a/pubnub/lib/src/subscribe/envelope.dart b/pubnub/lib/src/subscribe/envelope.dart
@@ -120,9 +120,26 @@ class PresenceEvent {
       .map((uuid) => UUID(uuid))
       .toList();
 
+  static bool isValidPresenceEvent(Envelope envelope) {
+    final payload = envelope.payload;
+    if (payload is! Map) return false;
+
+    final action = payload['action'];
+    final occupancy = payload['occupancy'];
+
+    if (action is! String ||
+        PresenceActionExtension.fromString(action) == PresenceAction.unknown) {
+      return false;
+    }
+    if (occupancy is! int) {
+      return false;
+    }
+    return true;
+  }
+
   PresenceEvent.fromEnvelope(this.envelope)
       : action = PresenceActionExtension.fromString(
-            envelope.payload['action'] as String?),
+            envelope.payload['action'] as String),
         uuid = envelope.payload['uuid'] != null
             ? UUID(envelope.payload['uuid'])
             : null,

diff --git a/pubnub/lib/src/subscribe/subscription.dart b/pubnub/lib/src/subscribe/subscription.dart
@@ -62,9 +62,10 @@ class Subscription {
   /// Will only emit when [withPresence] is true.
   Stream<PresenceEvent> get presence => _envelopesController.stream
       .where((envelope) =>
-          presenceChannels.contains(envelope.channel) ||
-          presenceChannels.contains(envelope.subscriptionPattern) ||
-          presenceChannelGroups.contains(envelope.subscriptionPattern))
+          PresenceEvent.isValidPresenceEvent(envelope) &&
+          (presenceChannels.contains(envelope.channel) ||
+              presenceChannels.contains(envelope.subscriptionPattern) ||
+              presenceChannelGroups.contains(envelope.subscriptionPattern)))
       .map<PresenceEvent>((envelope) => PresenceEvent.fromEnvelope(envelope));
 
   final Completer<void> _cancelCompleter = Completer();