Avoid crashing on childdevice property accesses (#732)

* Avoid crashing on childdevice property accesses

* Push updates from parent to child

kasa/tests/test_childdevice.py

@@ -1,4 +1,10 @@
+import inspect
+import sys
+
+import pytest
+
 from kasa.smartprotocol import _ChildProtocolWrapper
+from kasa.tapo.childdevice import ChildDevice
 
 from .conftest import strip_smart
 
@@ -19,12 +25,48 @@ def test_childdevice_init(dev, dummy_protocol, mocker):
 @strip_smart
 async def test_childdevice_update(dev, dummy_protocol, mocker):
     """Test that parent update updates children."""
-    assert len(dev.children) > 0
+    child_info = dev._last_update["child_info"]
+    child_list = child_info["child_device_list"]
+
+    assert len(dev.children) == child_info["sum"]
     first = dev.children[0]
 
-    child_update = mocker.patch.object(first, "update")
     await dev.update()
-    child_update.assert_called()
 
     assert dev._last_update != first._last_update
-    assert dev._last_update["child_info"]["child_device_list"][0] == first._last_update
+    assert child_list[0] == first._last_update
+
+
+@strip_smart
+@pytest.mark.skipif(
+    sys.version_info < (3, 11),
+    reason="exceptiongroup requires python3.11+",
+)
+async def test_childdevice_properties(dev: ChildDevice):
+    """Check that accessing childdevice properties do not raise exceptions."""
+    assert len(dev.children) > 0
+
+    first = dev.children[0]
+    assert first.is_strip_socket
+
+    # children do not have children
+    assert not first.children
+
+    def _test_property_getters():
+        """Try accessing all properties and return a list of encountered exceptions."""
+        exceptions = []
+        properties = inspect.getmembers(
+            first.__class__, lambda o: isinstance(o, property)
+        )
+        for prop in properties:
+            name, _ = prop
+            try:
+                _ = getattr(first, name)
+            except Exception as ex:
+                exceptions.append(ex)
+
+        return exceptions
+
+    exceptions = list(_test_property_getters())
+    if exceptions:
+        raise ExceptionGroup("Accessing child properties caused exceptions", exceptions)