Correct rest sensor configured to generate timestamps (#61429)

homeassistant/components/sensor/helpers.py

@@ -0,0 +1,38 @@
+"""Helpers for sensor entities."""
+from __future__ import annotations
+
+from datetime import date, datetime
+import logging
+
+from homeassistant.core import callback
+from homeassistant.util import dt as dt_util
+
+from . import SensorDeviceClass
+
+_LOGGER = logging.getLogger(__name__)
+
+
+@callback
+def async_parse_date_datetime(
+    value: str, entity_id: str, device_class: SensorDeviceClass | str | None
+) -> datetime | date | None:
+    """Parse datetime string to a data or datetime."""
+    if device_class == SensorDeviceClass.TIMESTAMP:
+        if (parsed_timestamp := dt_util.parse_datetime(value)) is None:
+            _LOGGER.warning("%s rendered invalid timestamp: %s", entity_id, value)
+            return None
+
+        if parsed_timestamp.tzinfo is None:
+            _LOGGER.warning(
+                "%s rendered timestamp without timezone: %s", entity_id, value
+            )
+            return None
+
+        return parsed_timestamp
+
+    # Date device class
+    if (parsed_date := dt_util.parse_date(value)) is not None:
+        return parsed_date
+
+    _LOGGER.warning("%s rendered invalid date %s", entity_id, value)
+    return None