Fix reconfiguring of Tasmota lights (#42288)

homeassistant/components/tasmota/light.py

@@ -80,10 +80,11 @@ class TasmotaLight(
 
         self._setup_from_entity()
 
-    async def discovery_update(self, update):
+    async def discovery_update(self, update, write_state=True):
         """Handle updated discovery message."""
+        await super().discovery_update(update, write_state=False)
         self._setup_from_entity()
-        await super().discovery_update(update)
+        self.async_write_ha_state()
 
     def _setup_from_entity(self):
         """(Re)Setup the entity."""

homeassistant/components/tasmota/mixins.py

@@ -38,11 +38,12 @@ class TasmotaEntity(Entity):
         await self._tasmota_entity.unsubscribe_topics()
         await super().async_will_remove_from_hass()
 
-    async def discovery_update(self, update):
+    async def discovery_update(self, update, write_state=True):
         """Handle updated discovery message."""
         self._tasmota_entity.config_update(update)
         await self._subscribe_topics()
-        self.async_write_ha_state()
+        if write_state:
+            self.async_write_ha_state()
 
     async def _subscribe_topics(self):
         """(Re)Subscribe to topics."""

tests/components/tasmota/test_common.py

@@ -385,7 +385,7 @@ async def help_test_discovery_update_unchanged(
     entity_id="test",
     name="Test",
 ):
-    """Test update of discovered component without changes.
+    """Test update of discovered component with and without changes.
 
     This is a test helper for the MqttDiscoveryUpdate mixin.
     """

tests/components/tasmota/test_light.py

@@ -2,6 +2,8 @@
 import copy
 import json
 
+from hatasmota.const import CONF_MAC
+
 from homeassistant.components import light
 from homeassistant.components.light import (
     SUPPORT_BRIGHTNESS,
@@ -771,6 +773,38 @@ async def test_unlinked_light2(hass, mqtt_mock, setup_tasmota):
     await _test_unlinked_light(hass, mqtt_mock, config, 2)
 
 
+async def test_discovery_update_reconfigure_light(
+    hass, mqtt_mock, caplog, setup_tasmota
+):
+    """Test reconfigure of discovered light."""
+    config = copy.deepcopy(DEFAULT_CONFIG)
+    config["rl"][0] = 2
+    config["lt_st"] = 1  # 1 channel light (Dimmer)
+    config2 = copy.deepcopy(DEFAULT_CONFIG)
+    config2["rl"][0] = 2
+    config2["lt_st"] = 3  # 3 channel light (RGB)
+    data1 = json.dumps(config)
+    data2 = json.dumps(config2)
+
+    # Simple dimmer
+    async_fire_mqtt_message(hass, f"{DEFAULT_PREFIX}/{config[CONF_MAC]}/config", data1)
+    await hass.async_block_till_done()
+    state = hass.states.get("light.test")
+    assert (
+        state.attributes.get("supported_features")
+        == SUPPORT_BRIGHTNESS | SUPPORT_TRANSITION
+    )
+
+    # Reconfigure as RGB light
+    async_fire_mqtt_message(hass, f"{DEFAULT_PREFIX}/{config[CONF_MAC]}/config", data2)
+    await hass.async_block_till_done()
+    state = hass.states.get("light.test")
+    assert (
+        state.attributes.get("supported_features")
+        == SUPPORT_BRIGHTNESS | SUPPORT_COLOR | SUPPORT_EFFECT | SUPPORT_TRANSITION
+    )
+
+
 async def test_availability_when_connection_lost(
     hass, mqtt_client_mock, mqtt_mock, setup_tasmota
 ):