Drop minus sign on negative zero (#86939)

* Drop minus sign on negative zero

* Add tests

homeassistant/components/sensor/__init__.py

@@ -9,6 +9,7 @@ from datetime import date, datetime, timedelta, timezone
 from decimal import Decimal, InvalidOperation as DecimalInvalidOperation
 import logging
 from math import ceil, floor, log10
+import re
 from typing import Any, Final, cast, final
 
 from homeassistant.config_entries import ConfigEntry
@@ -84,6 +85,8 @@ _LOGGER: Final = logging.getLogger(__name__)
 
 ENTITY_ID_FORMAT: Final = DOMAIN + ".{}"
 
+NEGATIVE_ZERO_PATTERN = re.compile(r"^-(0\.?0*)$")
+
 SCAN_INTERVAL: Final = timedelta(seconds=30)
 
 __all__ = [
@@ -647,8 +650,14 @@ class SensorEntity(Entity):
                 unit_of_measurement,
             )
             value = f"{converted_numerical_value:.{precision}f}"
+            # This can be replaced with adding the z option when we drop support for
+            # Python 3.10
+            value = NEGATIVE_ZERO_PATTERN.sub(r"\1", value)
         elif precision is not None:
             value = f"{numerical_value:.{precision}f}"
+            # This can be replaced with adding the z option when we drop support for
+            # Python 3.10
+            value = NEGATIVE_ZERO_PATTERN.sub(r"\1", value)
 
         # Validate unit of measurement used for sensors with a device class
         if (

tests/components/sensor/test_init.py

@@ -537,6 +537,15 @@ async def test_custom_unit(
             "29.921",  # Native precision is 3
             "1013.24",  # One digit of precision removed when converting
         ),
+        (
+            SensorDeviceClass.ATMOSPHERIC_PRESSURE,
+            UnitOfPressure.INHG,
+            UnitOfPressure.HPA,
+            -0.0001,
+            3,
+            "0.000",  # Native precision is 3
+            "0.00",  # One digit of precision removed when converting
+        ),
     ],
 )
 async def test_native_precision_scaling(
@@ -594,6 +603,14 @@ async def test_native_precision_scaling(
             "1000.000",
             "1000.0000",
         ),
+        (
+            SensorDeviceClass.DISTANCE,
+            UnitOfLength.KILOMETERS,
+            1,
+            -0.04,
+            "-0.040",
+            "0.0",  # Make sure minus is dropped
+        ),
     ],
 )
 async def test_custom_precision_native_precision(