Fix incorrect super().__getattr__() use on devicestatus

miio/click_common.py

@@ -329,6 +329,7 @@ def wrap(*args, **kwargs):
                 echo(json.dumps(ex.args[0], indent=indent))
                 return
 
+            # TODO: __json__ is not used anywhere and could be removed
             get_json_data_func = getattr(result, "__json__", None)
             data_variable = getattr(result, "data", None)
             if get_json_data_func is not None:

miio/devicestatus.py

@@ -13,6 +13,8 @@
     get_type_hints,
 )
 
+import attr
+
 from .descriptors import (
     ActionDescriptor,
     BooleanSettingDescriptor,
@@ -115,7 +117,6 @@ def embed(self, other: "DeviceStatus"):
 
         for name, sensor in other.sensors().items():
             final_name = f"{other_name}__{name}"
-            import attr
 
             self._sensors[final_name] = attr.evolve(sensor, property=final_name)
 
@@ -125,13 +126,13 @@ def embed(self, other: "DeviceStatus"):
 
     def __getattr__(self, item):
         """Overridden to lookup properties from embedded containers."""
-        if "__" not in item:
-            return super().__getattr__(item)
+        if item.startswith("__") and item.endswith("__"):
+            return super().__getattribute__(item)
 
-        if item == "__json__":  # special handling for custom json dunder
-            return None
+        embed, prop = item.split("__", maxsplit=1)
+        if not embed or not prop:
+            return super().__getattribute__(item)
 
-        embed, prop = item.split("__")
         return getattr(self._embedded[embed], prop)
 
 

miio/tests/test_devicestatus.py

@@ -76,6 +76,36 @@ def return_none(self):
     assert repr(NoneStatus()) == "<NoneStatus return_none=None>"
 
 
+def test_json_dunder():
+    """Make sure that getattr on __json__ returns None when not defined."""
+
+    class JsonDunder(DeviceStatus):
+        def __json__(self):
+            return "{}"
+
+    class NoJsonDunder(DeviceStatus):
+        pass
+
+    assert getattr(JsonDunder(), "__json__", None)() == "{}"
+    assert getattr(NoJsonDunder(), "__json__", None) is None
+
+
+def test_get_attribute(mocker):
+    """Make sure that __get_attribute__ works as expected."""
+
+    class TestStatus(DeviceStatus):
+        @property
+        def existing_attribute(self):
+            pass
+
+    status = TestStatus()
+    with pytest.raises(AttributeError):
+        _ = status.__missing_attribute
+
+    with pytest.raises(AttributeError):
+        _ = status.__missing_dunder__
+
+
 def test_sensor_decorator():
     class DecoratedProps(DeviceStatus):
         @property