Add round to half template method (#28948)

* added round to half method

Signed-off-by: Tobias Perschon <tobias@perschon.at>

* testcase for new round method

Signed-off-by: Tobias Perschon <tobias@perschon.at>

homeassistant/helpers/template.py

@@ -669,6 +669,8 @@ def forgiving_round(value, precision=0, method="common"):
             value = math.ceil(float(value) * multiplier) / multiplier
         elif method == "floor":
             value = math.floor(float(value) * multiplier) / multiplier
+        elif method == "half":
+            value = round(float(value) * 2) / 2
         else:
             # if method is common or something else, use common rounding
             value = round(float(value), precision)

tests/helpers/test_template.py

@@ -227,6 +227,13 @@ def test_rounding_value(hass):
         == "12.8"
     )
 
+    assert (
+        template.Template(
+            '{{ states.sensor.temperature.state | round(1, "half") }}', hass
+        ).async_render()
+        == "13.0"
+    )
+
 
 def test_rounding_value_get_original_value_on_error(hass):
     """Test rounding value get original value on error."""