Fix mqtt not publishing null payload payload to remove discovery (#118261)

homeassistant/components/mqtt/client.py

@@ -148,7 +148,7 @@ async def async_publish(
         )
     mqtt_data = hass.data[DATA_MQTT]
     outgoing_payload = payload
-    if not isinstance(payload, bytes):
+    if not isinstance(payload, bytes) and payload is not None:
         if not encoding:
             _LOGGER.error(
                 (

homeassistant/components/mqtt/mixins.py

@@ -647,7 +647,7 @@ async def async_remove_discovery_payload(
     after a restart of Home Assistant.
     """
     discovery_topic = discovery_data[ATTR_DISCOVERY_TOPIC]
-    await async_publish(hass, discovery_topic, "", retain=True)
+    await async_publish(hass, discovery_topic, None, retain=True)
 
 
 async def async_clear_discovery_topic_if_entity_removed(

tests/components/mqtt/test_device_tracker.py

@@ -294,7 +294,7 @@ async def test_cleanup_device_tracker(
 
     # Verify retained discovery topic has been cleared
     mqtt_mock.async_publish.assert_called_once_with(
-        "homeassistant/device_tracker/bla/config", "", 0, True
+        "homeassistant/device_tracker/bla/config", None, 0, True
     )
 
 

tests/components/mqtt/test_device_trigger.py

@@ -1358,7 +1358,7 @@ async def test_cleanup_trigger(
 
     # Verify retained discovery topic has been cleared
     mqtt_mock.async_publish.assert_called_once_with(
-        "homeassistant/device_automation/bla/config", "", 0, True
+        "homeassistant/device_automation/bla/config", None, 0, True
     )
 
 

tests/components/mqtt/test_discovery.py

@@ -829,7 +829,7 @@ async def test_cleanup_device(
     entity_registry: er.EntityRegistry,
     mqtt_mock_entry: MqttMockHAClientGenerator,
 ) -> None:
-    """Test discvered device is cleaned up when entry removed from device."""
+    """Test discovered device is cleaned up when entry removed from device."""
     mqtt_mock = await mqtt_mock_entry()
     assert await async_setup_component(hass, "config", {})
     ws_client = await hass_ws_client(hass)
@@ -874,7 +874,7 @@ async def test_cleanup_device(
 
     # Verify retained discovery topic has been cleared
     mqtt_mock.async_publish.assert_called_once_with(
-        "homeassistant/sensor/bla/config", "", 0, True
+        "homeassistant/sensor/bla/config", None, 0, True
     )
 
 
@@ -1015,9 +1015,9 @@ async def test_cleanup_device_multiple_config_entries(
     # Verify retained discovery topic has been cleared
     mqtt_mock.async_publish.assert_has_calls(
         [
-            call("homeassistant/sensor/bla/config", "", 0, True),
+            call("homeassistant/sensor/bla/config", None, 0, True),
-            call("homeassistant/tag/bla/config", "", 0, True),
+            call("homeassistant/tag/bla/config", None, 0, True),
-            call("homeassistant/device_automation/bla/config", "", 0, True),
+            call("homeassistant/device_automation/bla/config", None, 0, True),
         ],
         any_order=True,
     )
@@ -1616,11 +1616,11 @@ async def test_clear_config_topic_disabled_entity(
     # Assert all valid discovery topics are cleared
     assert mqtt_mock.async_publish.call_count == 2
     assert (
-        call("homeassistant/sensor/sbfspot_0/sbfspot_12345/config", "", 0, True)
+        call("homeassistant/sensor/sbfspot_0/sbfspot_12345/config", None, 0, True)
         in mqtt_mock.async_publish.mock_calls
     )
     assert (
-        call("homeassistant/sensor/sbfspot_0/sbfspot_12345_1/config", "", 0, True)
+        call("homeassistant/sensor/sbfspot_0/sbfspot_12345_1/config", None, 0, True)
         in mqtt_mock.async_publish.mock_calls
     )
 

tests/components/mqtt/test_init.py

@@ -223,49 +223,50 @@ async def test_publish(
 ) -> None:
     """Test the publish function."""
     mqtt_mock = await mqtt_mock_entry()
+    publish_mock: MagicMock = mqtt_mock._mqttc.publish
     await mqtt.async_publish(hass, "test-topic", "test-payload")
     await hass.async_block_till_done()
-    assert mqtt_mock.async_publish.called
+    assert publish_mock.called
-    assert mqtt_mock.async_publish.call_args[0] == (
+    assert publish_mock.call_args[0] == (
         "test-topic",
         "test-payload",
         0,
         False,
     )
-    mqtt_mock.reset_mock()
+    publish_mock.reset_mock()
 
     await mqtt.async_publish(hass, "test-topic", "test-payload", 2, True)
     await hass.async_block_till_done()
-    assert mqtt_mock.async_publish.called
+    assert publish_mock.called
-    assert mqtt_mock.async_publish.call_args[0] == (
+    assert publish_mock.call_args[0] == (
         "test-topic",
         "test-payload",
         2,
         True,
     )
-    mqtt_mock.reset_mock()
+    publish_mock.reset_mock()
 
     mqtt.publish(hass, "test-topic2", "test-payload2")
     await hass.async_block_till_done()
-    assert mqtt_mock.async_publish.called
+    assert publish_mock.called
-    assert mqtt_mock.async_publish.call_args[0] == (
+    assert publish_mock.call_args[0] == (
         "test-topic2",
         "test-payload2",
         0,
         False,
     )
-    mqtt_mock.reset_mock()
+    publish_mock.reset_mock()
 
     mqtt.publish(hass, "test-topic2", "test-payload2", 2, True)
     await hass.async_block_till_done()
-    assert mqtt_mock.async_publish.called
+    assert publish_mock.called
-    assert mqtt_mock.async_publish.call_args[0] == (
+    assert publish_mock.call_args[0] == (
         "test-topic2",
         "test-payload2",
         2,
         True,
     )
-    mqtt_mock.reset_mock()
+    publish_mock.reset_mock()
 
     # test binary pass-through
     mqtt.publish(
@@ -276,8 +277,8 @@ async def test_publish(
         False,
     )
     await hass.async_block_till_done()
-    assert mqtt_mock.async_publish.called
+    assert publish_mock.called
-    assert mqtt_mock.async_publish.call_args[0] == (
+    assert publish_mock.call_args[0] == (
         "test-topic3",
         b"\xde\xad\xbe\xef",
         0,
@@ -285,6 +286,25 @@ async def test_publish(
     )
     mqtt_mock.reset_mock()
 
+    # test null payload
+    mqtt.publish(
+        hass,
+        "test-topic3",
+        None,
+        0,
+        False,
+    )
+    await hass.async_block_till_done()
+    assert publish_mock.called
+    assert publish_mock.call_args[0] == (
+        "test-topic3",
+        None,
+        0,
+        False,
+    )
+
+    publish_mock.reset_mock()
+
 
 async def test_convert_outgoing_payload(hass: HomeAssistant) -> None:
     """Test the converting of outgoing MQTT payloads without template."""

tests/components/mqtt/test_tag.py

@@ -623,7 +623,7 @@ async def test_cleanup_tag(
 
     # Verify retained discovery topic has been cleared
     mqtt_mock.async_publish.assert_called_once_with(
-        "homeassistant/tag/bla1/config", "", 0, True
+        "homeassistant/tag/bla1/config", None, 0, True
     )
 
 

tests/conftest.py

@@ -927,7 +927,7 @@ def mqtt_client_mock(hass: HomeAssistant) -> Generator[MqttMockPahoClient, None,
 
         @ha.callback
         def _async_fire_mqtt_message(topic, payload, qos, retain):
-            async_fire_mqtt_message(hass, topic, payload, qos, retain)
+            async_fire_mqtt_message(hass, topic, payload or b"", qos, retain)
             mid = get_mid()
             hass.loop.call_soon(mock_client.on_publish, 0, 0, mid)
             return FakeInfo(mid)