Add dynamic device handling to Gatus (#176757)

homeassistant/components/gatus/binary_sensor.py

@@ -6,7 +6,7 @@ from homeassistant.components.binary_sensor import (
     BinarySensorDeviceClass,
     BinarySensorEntity,
 )
-from homeassistant.core import HomeAssistant
+from homeassistant.core import HomeAssistant, callback
 from homeassistant.helpers.entity_platform import AddConfigEntryEntitiesCallback
 
 from .coordinator import GatusConfigEntry, GatusDataUpdateCoordinator
@@ -23,10 +23,22 @@ async def async_setup_entry(
     """Set up the Gatus binary sensor platform."""
     coordinator = entry.runtime_data
 
-    async_add_entities(
-        GatusEndpointBinarySensor(coordinator, entry, endpoint_key)
-        for endpoint_key in coordinator.data
-    )
+    known_endpoints: set[str] = set()
+
+    @callback
+    def _check_endpoints() -> None:
+        current_endpoints = set(coordinator.data)
+        new_endpoints = current_endpoints - known_endpoints
+        if new_endpoints:
+            known_endpoints.update(new_endpoints)
+            async_add_entities(
+                GatusEndpointBinarySensor(coordinator, entry, endpoint_key)
+                for endpoint_key in new_endpoints
+            )
+        known_endpoints.intersection_update(current_endpoints)
+
+    _check_endpoints()
+    entry.async_on_unload(coordinator.async_add_listener(_check_endpoints))
 
 
 class GatusEndpointBinarySensor(GatusEndpointEntity, BinarySensorEntity):

homeassistant/components/gatus/quality_scale.yaml

@@ -63,7 +63,7 @@ rules:
   docs-supported-functions: done
   docs-troubleshooting: done
   docs-use-cases: done
-  dynamic-devices: todo
+  dynamic-devices: done
   entity-category: done
   entity-device-class: done
   entity-disabled-by-default:

tests/components/gatus/test_binary_sensor.py

@@ -164,3 +164,72 @@ async def test_binary_sensor_missing_status(
     state = hass.states.get("binary_sensor.backend_service")
     assert state is not None
     assert state.state == "off"
+
+
+async def test_binary_sensor_dynamic_endpoints(
+    hass: HomeAssistant,
+    mock_gatus_client: AsyncMock,
+    mock_config_entry: MockConfigEntry,
+    freezer: FrozenDateTimeFactory,
+) -> None:
+    """Test that new endpoints returned by the Gatus API at runtime dynamically create entities."""
+    await setup_integration(hass, mock_config_entry)
+
+    assert hass.states.get("binary_sensor.core_backend_service") is not None
+    assert hass.states.get("binary_sensor.core_new_service") is None
+
+    mock_gatus_client.get_endpoints_statuses.return_value = [
+        EndpointStatus(
+            key="backend_service",
+            name="Backend Service",
+            group="Core",
+            results=[Result(success=True, status=200)],
+        ),
+        EndpointStatus(
+            key="new_service",
+            name="New Service",
+            group="Core",
+            results=[Result(success=True, status=200)],
+        ),
+    ]
+
+    freezer.tick(30)
+    async_fire_time_changed(hass)
+    await hass.async_block_till_done()
+
+    assert hass.states.get("binary_sensor.core_new_service") is not None
+
+
+async def test_binary_sensor_readded_endpoint(
+    hass: HomeAssistant,
+    mock_gatus_client: AsyncMock,
+    mock_config_entry: MockConfigEntry,
+    freezer: FrozenDateTimeFactory,
+    entity_registry: er.EntityRegistry,
+) -> None:
+    """Test that a removed endpoint can be successfully re-added and has its entity recreated."""
+    await setup_integration(hass, mock_config_entry)
+
+    assert hass.states.get("binary_sensor.core_backend_service") is not None
+
+    mock_gatus_client.get_endpoints_statuses.return_value = []
+    freezer.tick(30)
+    async_fire_time_changed(hass)
+    await hass.async_block_till_done()
+
+    entity_registry.async_remove("binary_sensor.core_backend_service")
+    assert hass.states.get("binary_sensor.core_backend_service") is None
+
+    mock_gatus_client.get_endpoints_statuses.return_value = [
+        EndpointStatus(
+            key="backend_service",
+            name="Backend Service",
+            group="Core",
+            results=[Result(success=True, status=200)],
+        )
+    ]
+    freezer.tick(30)
+    async_fire_time_changed(hass)
+    await hass.async_block_till_done()
+
+    assert hass.states.get("binary_sensor.core_backend_service") is not None