Correct rest sensor configured to generate timestamps (#61429)

tests/components/sensor/test_helpers.py

@@ -0,0 +1,38 @@
+"""The test for sensor helpers."""
+from homeassistant.components.sensor import SensorDeviceClass
+from homeassistant.components.sensor.helpers import async_parse_date_datetime
+
+
+def test_async_parse_datetime(caplog):
+    """Test async_parse_date_datetime."""
+    entity_id = "sensor.timestamp"
+    device_class = SensorDeviceClass.TIMESTAMP
+    assert (
+        async_parse_date_datetime(
+            "2021-12-12 12:12Z", entity_id, device_class
+        ).isoformat()
+        == "2021-12-12T12:12:00+00:00"
+    )
+    assert not caplog.text
+
+    # No timezone
+    assert (
+        async_parse_date_datetime("2021-12-12 12:12", entity_id, device_class) is None
+    )
+    assert "sensor.timestamp rendered timestamp without timezone" in caplog.text
+
+    # Invalid timestamp
+    assert async_parse_date_datetime("12 past 12", entity_id, device_class) is None
+    assert "sensor.timestamp rendered invalid timestamp: 12 past 12" in caplog.text
+
+    device_class = SensorDeviceClass.DATE
+    caplog.clear()
+    assert (
+        async_parse_date_datetime("2021-12-12", entity_id, device_class).isoformat()
+        == "2021-12-12"
+    )
+    assert not caplog.text
+
+    # Invalid date
+    assert async_parse_date_datetime("December 12th", entity_id, device_class) is None
+    assert "sensor.timestamp rendered invalid date December 12th" in caplog.text