Handle Matter nodes that become available after startup is done

homeassistant/components/matter/adapter.py

@@ -52,11 +52,27 @@ def register_platform_handler(
 
     async def setup_nodes(self) -> None:
         """Set up all existing nodes and subscribe to new nodes."""
+        initialized_nodes: set[int] = set()
         for node in self.matter_client.get_nodes():
+            if not node.available:
+                # ignore un-initialized nodes at startup
+                # catch them later when they become available.
+                continue
+            initialized_nodes.add(node.node_id)
             self._setup_node(node)
 
         def node_added_callback(event: EventType, node: MatterNode) -> None:
             """Handle node added event."""
+            initialized_nodes.add(node.node_id)
+            self._setup_node(node)
+
+        def node_updated_callback(event: EventType, node: MatterNode) -> None:
+            """Handle node updated event."""
+            if node.node_id in initialized_nodes:
+                return
+            if not node.available:
+                return
+            initialized_nodes.add(node.node_id)
             self._setup_node(node)
 
         def endpoint_added_callback(event: EventType, data: dict[str, int]) -> None:
@@ -116,6 +132,11 @@ def node_removed_callback(event: EventType, node_id: int) -> None:
                 callback=node_added_callback, event_filter=EventType.NODE_ADDED
             )
         )
+        self.config_entry.async_on_unload(
+            self.matter_client.subscribe_events(
+                callback=node_updated_callback, event_filter=EventType.NODE_UPDATED
+            )
+        )
 
     def _setup_node(self, node: MatterNode) -> None:
         """Set up an node."""

tests/components/matter/test_adapter.py

@@ -144,10 +144,10 @@ async def test_node_added_subscription(
     integration: MagicMock,
 ) -> None:
     """Test subscription to new devices work."""
-    assert matter_client.subscribe_events.call_count == 4
+    assert matter_client.subscribe_events.call_count == 5
     assert (
         matter_client.subscribe_events.call_args.kwargs["event_filter"]
-        == EventType.NODE_ADDED
+        == EventType.NODE_UPDATED
     )
 
     node_added_callback = matter_client.subscribe_events.call_args.kwargs["callback"]