check for empty or missing values when processing state messages for MQTT light entities using 'template' schema

Author: sumnerboy12

homeassistant/components/mqtt/light/schema_template.py

@@ -204,73 +204,107 @@ def _update_color_mode(self) -> None:
     @callback
     def _state_received(self, msg: ReceiveMessage) -> None:
         """Handle new MQTT messages."""
-        state = self._value_templates[CONF_STATE_TEMPLATE](msg.payload)
-        if state == STATE_ON:
+        state_value = self._value_templates[CONF_STATE_TEMPLATE](msg.payload)
+        if not state_value:
+            _LOGGER.debug(
+                "Ignoring message from '%s' with empty state value", msg.topic
+            )
+        elif state_value == STATE_ON:
             self._attr_is_on = True
-        elif state == STATE_OFF:
+        elif state_value == STATE_OFF:
             self._attr_is_on = False
-        elif state == PAYLOAD_NONE:
+        elif state_value == PAYLOAD_NONE:
             self._attr_is_on = None
         else:
-            _LOGGER.warning("Invalid state value received")
+            _LOGGER.warning("Invalid state value received from '%s'", state_value)
 
         if CONF_BRIGHTNESS_TEMPLATE in self._config:
-            try:
-                if brightness := int(
-                    self._value_templates[CONF_BRIGHTNESS_TEMPLATE](msg.payload)
-                ):
-                    self._attr_brightness = brightness
-                else:
-                    _LOGGER.debug(
-                        "Ignoring zero brightness value for entity %s",
-                        self.entity_id,
+            brightness_value = self._value_templates[CONF_BRIGHTNESS_TEMPLATE](
+                msg.payload
+            )
+            if not brightness_value:
+                _LOGGER.debug(
+                    "Ignoring message from '%s' with empty brightness value",
+                    msg.topic,
+                )
+            else:
+                try:
+                    if brightness := int(brightness_value):
+                        self._attr_brightness = brightness
+                    else:
+                        _LOGGER.debug(
+                            "Ignoring zero brightness value for entity %s",
+                            self.entity_id,
+                        )
+                except ValueError:
+                    _LOGGER.warning(
+                        "Invalid brightness value received from %s", msg.topic
                     )
 
-            except ValueError:
-                _LOGGER.warning("Invalid brightness value received from %s", msg.topic)
-
         if CONF_COLOR_TEMP_TEMPLATE in self._config:
-            try:
-                color_temp = self._value_templates[CONF_COLOR_TEMP_TEMPLATE](
-                    msg.payload
-                )
-                self._attr_color_temp_kelvin = (
-                    int(color_temp)
-                    if self._color_temp_kelvin
-                    else color_util.color_temperature_mired_to_kelvin(int(color_temp))
-                    if color_temp != "None"
-                    else None
+            color_temp_value = self._value_templates[CONF_COLOR_TEMP_TEMPLATE](
+                msg.payload
+            )
+            if not color_temp_value:
+                _LOGGER.debug(
+                    "Ignoring message from '%s' with empty color temperature value",
+                    msg.topic,
                 )
-            except ValueError:
-                _LOGGER.warning("Invalid color temperature value received")
+            else:
+                try:
+                    self._attr_color_temp_kelvin = (
+                        int(color_temp_value)
+                        if self._color_temp_kelvin
+                        else color_util.color_temperature_mired_to_kelvin(
+                            int(color_temp_value)
+                        )
+                        if color_temp_value != "None"
+                        else None
+                    )
+                except ValueError:
+                    _LOGGER.warning(
+                        "Invalid color temperature value received from %s", msg.topic
+                    )
 
         if (
             CONF_RED_TEMPLATE in self._config
             and CONF_GREEN_TEMPLATE in self._config
             and CONF_BLUE_TEMPLATE in self._config
         ):
-            try:
-                red = self._value_templates[CONF_RED_TEMPLATE](msg.payload)
-                green = self._value_templates[CONF_GREEN_TEMPLATE](msg.payload)
-                blue = self._value_templates[CONF_BLUE_TEMPLATE](msg.payload)
-                if red == "None" and green == "None" and blue == "None":
-                    self._attr_hs_color = None
-                else:
+            red_value = self._value_templates[CONF_RED_TEMPLATE](msg.payload)
+            green_value = self._value_templates[CONF_GREEN_TEMPLATE](msg.payload)
+            blue_value = self._value_templates[CONF_BLUE_TEMPLATE](msg.payload)
+            if not red_value or not green_value or not blue_value:
+                _LOGGER.debug(
+                    "Ignoring message from '%s' with empty color value", msg.topic
+                )
+            elif red_value == "None" and green_value == "None" and blue_value == "None":
+                self._attr_hs_color = None
+            else:
+                try:
                     self._attr_hs_color = color_util.color_RGB_to_hs(
-                        int(red), int(green), int(blue)
+                        int(red_value), int(green_value), int(blue_value)
                     )
-                self._update_color_mode()
-            except ValueError:
-                _LOGGER.warning("Invalid color value received")
+                    self._update_color_mode()
+                except ValueError:
+                    _LOGGER.warning("Invalid color value received from %s", msg.topic)
 
         if CONF_EFFECT_TEMPLATE in self._config:
-            effect = str(self._value_templates[CONF_EFFECT_TEMPLATE](msg.payload))
-            if (
-                effect_list := self._config[CONF_EFFECT_LIST]
-            ) and effect in effect_list:
-                self._attr_effect = effect
+            effect_value = self._value_templates[CONF_EFFECT_TEMPLATE](msg.payload)
+            if not effect_value:
+                _LOGGER.debug(
+                    "Ignoring message from '%s' with empty effect value", msg.topic
+                )
+            elif (effect_list := self._config[CONF_EFFECT_LIST]) and str(
+                effect_value
+            ) in effect_list:
+                self._attr_effect = str(effect_value)
             else:
-                _LOGGER.warning("Unsupported effect value received")
+                _LOGGER.warning(
+                    "Unsupported effect value '%s' received from %s",
+                    effect_value,
+                    msg.topic,
+                )
 
     @callback
     def _prepare_subscribe_topics(self) -> None: