From 6e56e9c98560b99b1d5382492bd4737a487c3c97 Mon Sep 17 00:00:00 2001
From: Sylvester Kaczmarek
 <16242628+sylvesterkaczmarek@users.noreply.github.com>
Date: Fri, 21 Aug 2026 12:52:33 +0100
Subject: [PATCH 1/3] Preserve render product lists for noop annotator

---
 .../isaacsim.core.nodes/python/impl/base_writer_node.py    | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/source/extensions/isaacsim.core.nodes/python/impl/base_writer_node.py b/source/extensions/isaacsim.core.nodes/python/impl/base_writer_node.py
index e23e955057..a9d8aa0cce 100644
--- a/source/extensions/isaacsim.core.nodes/python/impl/base_writer_node.py
+++ b/source/extensions/isaacsim.core.nodes/python/impl/base_writer_node.py
@@ -140,7 +140,12 @@ def _process_activation_requests(self, event: carb.eventdispatcher.Event) -> Non
                         noop = rep.AnnotatorRegistry.get_annotator(
                             "IsaacNoop",
                         )
-                        noop.attach([request.render_product_path])
+                        render_products = (
+                            request.render_product_path
+                            if isinstance(request.render_product_path, list)
+                            else [request.render_product_path]
+                        )
+                        noop.attach(render_products)
                         carb.log_info(f"Attaching:\n{request}")
                     else:
                         request.writer.detach()

From aba4fe4c0dd82ad6e744ef37416c6e54c581f80b Mon Sep 17 00:00:00 2001
From: Sylvester Kaczmarek
 <16242628+sylvesterkaczmarek@users.noreply.github.com>
Date: Fri, 21 Aug 2026 12:53:28 +0100
Subject: [PATCH 2/3] Cover multi-render-product writer attachment

---
 .../python/tests/test_base_writer_node.py     | 41 +++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 source/extensions/isaacsim.core.nodes/python/tests/test_base_writer_node.py

diff --git a/source/extensions/isaacsim.core.nodes/python/tests/test_base_writer_node.py b/source/extensions/isaacsim.core.nodes/python/tests/test_base_writer_node.py
new file mode 100644
index 0000000000..d5014db0b6
--- /dev/null
+++ b/source/extensions/isaacsim.core.nodes/python/tests/test_base_writer_node.py
@@ -0,0 +1,41 @@
+# SPDX-FileCopyrightText: Copyright (c) 2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+"""Tests for BaseWriterNode render-product attachment handling."""
+
+from unittest.mock import MagicMock, patch
+
+import omni.kit.test
+from isaacsim.core.nodes import BaseWriterNode, WriterRequest
+
+
+class TestBaseWriterNode(omni.kit.test.TestCase):
+    """Validate writer activation requests."""
+
+    @patch("isaacsim.core.nodes.impl.base_writer_node.Usd.EditContext")
+    @patch("isaacsim.core.nodes.impl.base_writer_node.omni.usd.get_context")
+    @patch("isaacsim.core.nodes.impl.base_writer_node.rep.AnnotatorRegistry.get_annotator")
+    def test_noop_annotator_preserves_render_product_list(
+        self, mock_get_annotator: MagicMock, mock_get_context: MagicMock, mock_edit_context: MagicMock
+    ) -> None:
+        """A list of render products must not be wrapped in another list."""
+        stage = MagicMock()
+        mock_get_context.return_value.get_stage.return_value = stage
+        mock_edit_context.return_value.__enter__.return_value = None
+        mock_edit_context.return_value.__exit__.return_value = False
+
+        writer = MagicMock()
+        writer.node_type_id = "TestWriter"
+        writer._kwargs = {}
+        writer._annotators = []
+        noop = mock_get_annotator.return_value
+
+        render_products = ["/Render/ProductA", "/Render/ProductB"]
+        node = BaseWriterNode()
+        node.post_attach = MagicMock()
+        node._requests = [WriterRequest(writer, render_products, True)]
+
+        node._process_activation_requests(MagicMock())
+
+        writer.attach.assert_called_once_with(render_products)
+        noop.attach.assert_called_once_with(render_products)

From d20e98eb98661d0981ccd8159f69180fb7bd9d9c Mon Sep 17 00:00:00 2001
From: Sylvester Kaczmarek
 <16242628+sylvesterkaczmarek@users.noreply.github.com>
Date: Fri, 21 Aug 2026 12:57:57 +0100
Subject: [PATCH 3/3] Use async Kit test base for writer regression

---
 .../isaacsim.core.nodes/python/tests/test_base_writer_node.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/source/extensions/isaacsim.core.nodes/python/tests/test_base_writer_node.py b/source/extensions/isaacsim.core.nodes/python/tests/test_base_writer_node.py
index d5014db0b6..fd7d5de1fd 100644
--- a/source/extensions/isaacsim.core.nodes/python/tests/test_base_writer_node.py
+++ b/source/extensions/isaacsim.core.nodes/python/tests/test_base_writer_node.py
@@ -9,13 +9,13 @@
 from isaacsim.core.nodes import BaseWriterNode, WriterRequest
 
 
-class TestBaseWriterNode(omni.kit.test.TestCase):
+class TestBaseWriterNode(omni.kit.test.AsyncTestCase):
     """Validate writer activation requests."""
 
     @patch("isaacsim.core.nodes.impl.base_writer_node.Usd.EditContext")
     @patch("isaacsim.core.nodes.impl.base_writer_node.omni.usd.get_context")
     @patch("isaacsim.core.nodes.impl.base_writer_node.rep.AnnotatorRegistry.get_annotator")
-    def test_noop_annotator_preserves_render_product_list(
+    async def test_noop_annotator_preserves_render_product_list(
         self, mock_get_annotator: MagicMock, mock_get_context: MagicMock, mock_edit_context: MagicMock
     ) -> None:
         """A list of render products must not be wrapped in another list."""