Fix MQTT retained event messages should be discarded (#106425)

homeassistant/components/mqtt/event.py

@@ -35,7 +35,6 @@ from .mixins import (
     MQTT_ENTITY_COMMON_SCHEMA,
     MqttEntity,
     async_setup_entity_entry_helper,
-    write_state_on_attr_change,
 )
 from .models import (
     MqttValueTemplate,
@@ -43,6 +42,7 @@ from .models import (
     ReceiveMessage,
     ReceivePayloadType,
 )
+from .util import get_mqtt_data
 
 _LOGGER = logging.getLogger(__name__)
 
@@ -120,9 +120,15 @@ class MqttEvent(MqttEntity, EventEntity):
 
         @callback
         @log_messages(self.hass, self.entity_id)
-        @write_state_on_attr_change(self, {"state"})
         def message_received(msg: ReceiveMessage) -> None:
             """Handle new MQTT messages."""
+            if msg.retain:
+                _LOGGER.debug(
+                    "Ignoring event trigger from replayed retained payload '%s' on topic %s",
+                    msg.payload,
+                    msg.topic,
+                )
+                return
             event_attributes: dict[str, Any] = {}
             event_type: str
             payload = self._template(msg.payload, PayloadSentinel.DEFAULT)
@@ -183,6 +189,8 @@ class MqttEvent(MqttEntity, EventEntity):
                     payload,
                 )
                 return
+            mqtt_data = get_mqtt_data(self.hass)
+            mqtt_data.state_write_requests.write_state_request(self)
 
         topics["state_topic"] = {
             "topic": self._config[CONF_STATE_TOPIC],

tests/components/mqtt/test_event.py

@@ -88,6 +88,68 @@ async def test_setting_event_value_via_mqtt_message(
     assert state.attributes.get("duration") == "short"
 
 
+@pytest.mark.freeze_time("2023-08-01 00:00:00+00:00")
+@pytest.mark.parametrize("hass_config", [DEFAULT_CONFIG])
+async def test_multiple_events_are_all_updating_the_state(
+    hass: HomeAssistant, mqtt_mock_entry: MqttMockHAClientGenerator
+) -> None:
+    """Test all events are respected and trigger a state write."""
+    await mqtt_mock_entry()
+    with patch(
+        "homeassistant.components.mqtt.mixins.MqttEntity.async_write_ha_state"
+    ) as mock_async_ha_write_state:
+        async_fire_mqtt_message(
+            hass, "test-topic", '{"event_type": "press", "duration": "short" }'
+        )
+        assert len(mock_async_ha_write_state.mock_calls) == 1
+        async_fire_mqtt_message(
+            hass, "test-topic", '{"event_type": "press", "duration": "short" }'
+        )
+        assert len(mock_async_ha_write_state.mock_calls) == 2
+
+
+@pytest.mark.parametrize("hass_config", [DEFAULT_CONFIG])
+async def test_handling_retained_event_payloads(
+    hass: HomeAssistant, mqtt_mock_entry: MqttMockHAClientGenerator
+) -> None:
+    """Test if event messages with a retained flag are ignored."""
+    await mqtt_mock_entry()
+    with patch(
+        "homeassistant.components.mqtt.mixins.MqttEntity.async_write_ha_state"
+    ) as mock_async_ha_write_state:
+        async_fire_mqtt_message(
+            hass,
+            "test-topic",
+            '{"event_type": "press", "duration": "short" }',
+            retain=True,
+        )
+        assert len(mock_async_ha_write_state.mock_calls) == 0
+
+        async_fire_mqtt_message(
+            hass,
+            "test-topic",
+            '{"event_type": "press", "duration": "short" }',
+            retain=False,
+        )
+        assert len(mock_async_ha_write_state.mock_calls) == 1
+
+        async_fire_mqtt_message(
+            hass,
+            "test-topic",
+            '{"event_type": "press", "duration": "short" }',
+            retain=True,
+        )
+        assert len(mock_async_ha_write_state.mock_calls) == 1
+
+        async_fire_mqtt_message(
+            hass,
+            "test-topic",
+            '{"event_type": "press", "duration": "short" }',
+            retain=False,
+        )
+        assert len(mock_async_ha_write_state.mock_calls) == 2
+
+
 @pytest.mark.freeze_time("2023-08-01 00:00:00+00:00")
 @pytest.mark.parametrize("hass_config", [DEFAULT_CONFIG])
 @pytest.mark.parametrize(