Add lovelace compatiblity code (#136617)

* Add lovelace compatiblity code

* Docstring

* Add tests

homeassistant/components/lovelace/__init__.py

@@ -15,6 +15,7 @@ from homeassistant.const import CONF_FILENAME, CONF_MODE, CONF_RESOURCES
 from homeassistant.core import HomeAssistant, ServiceCall, callback
 from homeassistant.exceptions import HomeAssistantError
 from homeassistant.helpers import collection, config_validation as cv
+from homeassistant.helpers.frame import report_usage
 from homeassistant.helpers.service import async_register_admin_service
 from homeassistant.helpers.typing import ConfigType
 from homeassistant.loader import async_get_integration
@@ -99,6 +100,32 @@ class LovelaceData:
     resources: resources.ResourceYAMLCollection | resources.ResourceStorageCollection
     yaml_dashboards: dict[str | None, ConfigType]
 
+    def __getitem__(self, name: str) -> Any:
+        """Enable method for compatibility reason.
+
+        Following migration from an untyped dict to a dataclass in
+        https://github.com/home-assistant/core/pull/136313
+        """
+        report_usage(
+            f"accessed lovelace_data['{name}'] instead of lovelace_data.{name}",
+            breaks_in_ha_version="2026.2",
+        )
+        return getattr(self, name)
+
+    def get(self, name: str, default: Any = None) -> Any:
+        """Enable method for compatibility reason.
+
+        Following migration from an untyped dict to a dataclass in
+        https://github.com/home-assistant/core/pull/136313
+        """
+        report_usage(
+            f"accessed lovelace_data.get('{name}') instead of lovelace_data.{name}",
+            breaks_in_ha_version="2026.2",
+        )
+        if hasattr(self, name):
+            return getattr(self, name)
+        return default
+
 
 async def async_setup(hass: HomeAssistant, config: ConfigType) -> bool:
     """Set up the Lovelace commands."""

tests/components/lovelace/test_init.py

@@ -38,3 +38,44 @@ async def test_create_dashboards_when_onboarded(
     response = await client.receive_json()
     assert response["success"]
     assert response["result"] == []
+
+
+async def test_hass_data_compatibility(
+    hass: HomeAssistant,
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Test compatibility for external access.
+
+    See:
+    https://github.com/hacs/integration/blob/4a820e8b1b066bc54a1c9c61102038af6c030603
+    /custom_components/hacs/repositories/plugin.py#L173
+    """
+    expected = (
+        "Detected that integration 'lovelace' accessed lovelace_data.get('resources')"
+        " instead of lovelace_data.resources at"
+    )
+
+    assert await async_setup_component(hass, "lovelace", {})
+
+    assert (lovelace_data := hass.data.get("lovelace")) is not None
+    assert expected not in caplog.text
+
+    # Direct access to resources is fine
+    assert lovelace_data.resources is not None
+    assert (
+        "Detected that integration 'lovelace' accessed lovelace_data" not in caplog.text
+    )
+
+    # Dict compatibility logs warning
+    assert lovelace_data["resources"] is not None
+    assert (
+        "Detected that integration 'lovelace' accessed lovelace_data['resources']"
+        in caplog.text
+    )
+
+    # Dict get compatibility logs warning
+    assert lovelace_data.get("resources") is not None
+    assert (
+        "Detected that integration 'lovelace' accessed lovelace_data.get('resources')"
+        in caplog.text
+    )