Ensure numeric template sensors only use numbers in _attr_native_state (#162878)

Co-authored-by: Erik Montnemery <erik@montnemery.com>

homeassistant/components/template/sensor.py

@@ -256,6 +256,9 @@ class AbstractTemplateSensor(AbstractTemplateEntity, RestoreSensor):
         self, result: Any
     ) -> StateType | date | datetime | Decimal | None:
         """Validate the state."""
+        if self._numeric_state_expected:
+            return template_validators.number(self, CONF_STATE)(result)
+
         if result is None or self.device_class not in (
             SensorDeviceClass.DATE,
             SensorDeviceClass.TIMESTAMP,

tests/components/template/test_config_flow.py

@@ -1306,7 +1306,7 @@ async def test_config_flow_preview_template_error(
     [
         (
             "sensor",
-            "{{ states('sensor.one') }}",
+            "{{ 1.0 / states('sensor.one') | float(0.0) }}",
             {"unit_of_measurement": "°C"},
         ),
     ],
@@ -1350,14 +1350,7 @@ async def test_config_flow_preview_bad_state(
     assert msg["result"] is None
 
     msg = await client.receive_json()
-    assert msg["event"] == {
-        "error": (
-            "Sensor None has device class 'None', state class 'None' unit '°C' "
-            "and suggested precision 'None' thus indicating it has a numeric "
-            "value; however, it has the non-numeric value: 'unknown' (<class "
-            "'str'>)"
-        ),
-    }
+    assert msg["event"] == {"error": "ZeroDivisionError: division by zero"}
 
 
 @pytest.mark.parametrize(

tests/components/template/test_sensor.py

@@ -692,7 +692,7 @@ async def test_sun_renders_once_per_sensor(hass: HomeAssistant) -> None:
         hass.states.async_set("sun.sun", {"elevation": 50, "next_rising": later})
         await hass.async_block_till_done()
 
-    assert hass.states.get("sensor.solar_angle").state == "75"
+    assert hass.states.get("sensor.solar_angle").state == "75.0"
     assert hass.states.get("sensor.sunrise").state == "75"
 
     assert len(async_render_calls) == 2
@@ -1524,7 +1524,7 @@ async def test_last_reset(hass: HomeAssistant, expected: str) -> None:
 
     state = hass.states.get(TEST_SENSOR.entity_id)
     assert state is not None
-    assert state.state == "0"
+    assert state.state == "0.0"
     assert state.attributes["state_class"] == "total"
     assert state.attributes["last_reset"] == expected
 
@@ -1553,7 +1553,7 @@ async def test_invalid_last_reset(
 
     state = hass.states.get(TEST_SENSOR.entity_id)
     assert state is not None
-    assert state.state == "0"
+    assert state.state == "0.0"
     assert state.attributes.get("last_reset") is None
 
     err = "Received invalid sensor last_reset: not a datetime for entity"
@@ -1956,3 +1956,40 @@ async def test_flow_preview(
     )
 
     assert state["state"] == "0.0"
+
+
+@pytest.mark.parametrize(
+    ("count", "config", "state_template"),
+    [
+        (
+            1,
+            {
+                "device_class": "temperature",
+                "state_class": "measurement",
+                "unit_of_measurement": "°C",
+            },
+            "{{ states('sensor.test_state') }}",
+        )
+    ],
+)
+@pytest.mark.parametrize(
+    "style", [ConfigurationStyle.MODERN, ConfigurationStyle.TRIGGER]
+)
+@pytest.mark.usefixtures("setup_state_sensor")
+async def test_numeric_sensor_recovers_from_exception(hass: HomeAssistant) -> None:
+    """Test template."""
+    assert hass.states.get(TEST_SENSOR.entity_id).state == STATE_UNKNOWN
+
+    for set_state, expected_state in (
+        ("0.0", "0.0"),
+        ("unavailable", STATE_UNKNOWN),
+        ("1.0", "1.0"),
+        ("unknown", STATE_UNKNOWN),
+        ("2.0", "2.0"),
+        ("kjfdah", STATE_UNKNOWN),
+        ("3.0", "3.0"),
+        ("3.x", STATE_UNKNOWN),
+        ("4.0", "4.0"),
+    ):
+        await async_trigger(hass, TEST_STATE_SENSOR, set_state)
+        assert hass.states.get(TEST_SENSOR.entity_id).state == expected_state