From 950663f456acf5d53cde951d1e021b41d1b2b33f Mon Sep 17 00:00:00 2001
From: Oide Brett <32061073+oidebrett@users.noreply.github.com>
Date: Tue, 18 Jun 2024 09:54:50 +0100
Subject: [PATCH] Edge case defect when importing the first test node into
 dashboard (#763)

---
 matter_server/server/device_controller.py | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/matter_server/server/device_controller.py b/matter_server/server/device_controller.py
index d466a423..c4cb34a8 100644
--- a/matter_server/server/device_controller.py
+++ b/matter_server/server/device_controller.py
@@ -865,7 +865,12 @@ async def import_test_node(self, dump: str) -> None:
         else:
             dump_nodes = dump_data["data"]["server"]["nodes"]
         # node ids > 900000 are reserved for test nodes
-        next_test_node_id = max(*(x for x in self._nodes), TEST_NODE_START) + 1
+        if self._nodes:
+            next_test_node_id = max(*(x for x in self._nodes), TEST_NODE_START) + 1
+        else:
+            # an empty self._nodes dict evaluates to false so we set the first
+            # test node id to TEST_NODE_START
+            next_test_node_id = TEST_NODE_START
         for node_dict in dump_nodes:
             node = dataclass_from_dict(MatterNodeData, node_dict, strict=True)
             node.node_id = next_test_node_id