Fix Extensions.triggerAction: capture parent session before tab detaches

Tab targets are filtered out via SilentDetachAsync which removes them from
Connection._sessions. When CdpPage is constructed shortly after, its call to
client.ParentSession can no longer find the tab session by ID, causing
TabId to fall back to the page target ID instead of the tab target ID.
Chrome then rejects Extensions.triggerAction with "Action can only be
triggered on a tab target."

Fix: capture the parent session object reference at session-creation time
(before SilentDetachAsync runs) so CdpPage always gets the correct tab
target ID regardless of session lifecycle.

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

Author: kblok

lib/PuppeteerSharp/Cdp/CdpCDPSession.cs

@@ -40,21 +40,24 @@ public class CdpCDPSession : CDPSession
     private readonly ConcurrentDictionary<int, MessageTask> _callbacks = new();
     private readonly string _parentSessionId;
     private readonly TargetType _targetType;
+    private readonly CdpCDPSession _parentSessionRef;
     private int _lastId;
 
-    internal CdpCDPSession(Connection connection, TargetType targetType, string sessionId, string parentSessionId)
+    internal CdpCDPSession(Connection connection, TargetType targetType, string sessionId, string parentSessionId, CdpCDPSession parentSessionRef = null)
     {
         Connection = connection;
         _targetType = targetType;
         Id = sessionId;
         _parentSessionId = parentSessionId;
+        _parentSessionRef = parentSessionRef;
     }
 
     /// <inheritdoc />
     public override bool Detached => Connection.IsClosed || IsClosed;
 
     internal override CDPSession ParentSession
-        => string.IsNullOrEmpty(_parentSessionId) ? this : Connection.GetSession(_parentSessionId) ?? this;
+        => _parentSessionRef
+            ?? (string.IsNullOrEmpty(_parentSessionId) ? this : Connection.GetSession(_parentSessionId) ?? this);
 
     internal bool IsClosed { get; private set; }
 

lib/PuppeteerSharp/Cdp/Connection.cs

@@ -329,7 +329,11 @@ private void ProcessIncomingMessage(ConnectionResponse obj)
             {
                 var param = obj.Params?.ToObject<ConnectionResponseParams>();
                 var sessionId = param.SessionId;
-                var session = new CdpCDPSession(this, param.TargetInfo.Type, sessionId, obj.SessionId);
+
+                // Capture the parent session reference now, before it may be removed from _sessions
+                // by SilentDetachAsync (tab targets are filtered and detached quickly).
+                var attachingParentSession = string.IsNullOrEmpty(obj.SessionId) ? null : GetSession(obj.SessionId);
+                var session = new CdpCDPSession(this, param.TargetInfo.Type, sessionId, obj.SessionId, attachingParentSession);
                 _sessions.AddItem(sessionId, session);
 
                 SessionAttached?.Invoke(this, new SessionEventArgs(session));