Add additional rules for converting distances (#80940)

* Add additional rules for converting distances

* Convert in to mm

* Adjust existing tests

* Add test

homeassistant/util/unit_system.py

@@ -9,8 +9,14 @@ import voluptuous as vol
 from homeassistant.const import (
     ACCUMULATED_PRECIPITATION,
     LENGTH,
+    LENGTH_CENTIMETERS,
+    LENGTH_FEET,
+    LENGTH_INCHES,
     LENGTH_KILOMETERS,
+    LENGTH_METERS,
     LENGTH_MILES,
+    LENGTH_MILLIMETERS,
+    LENGTH_YARD,
     MASS,
     MASS_GRAMS,
     MASS_KILOGRAMS,
@@ -92,8 +98,8 @@ class UnitSystem:
         name: str,
         *,
         accumulated_precipitation: str,
+        conversions: dict[tuple[str | None, str | None], str],
         length: str,
-        length_conversions: dict[str | None, str],
         mass: str,
         pressure: str,
         temperature: str,
@@ -126,7 +132,7 @@ class UnitSystem:
         self.pressure_unit = pressure
         self.volume_unit = volume
         self.wind_speed_unit = wind_speed
-        self._length_conversions = length_conversions
+        self._conversions = conversions
 
     @property
     def name(self) -> str:
@@ -226,10 +232,7 @@ class UnitSystem:
         original_unit: str | None,
     ) -> str | None:
         """Return converted unit given a device class or an original unit."""
-        if device_class == "distance":
+        return self._conversions.get((device_class, original_unit))
-            return self._length_conversions.get(original_unit)
-
-        return None
 
 
 def get_unit_system(key: str) -> UnitSystem:
@@ -259,8 +262,14 @@ validate_unit_system = vol.All(
 METRIC_SYSTEM = UnitSystem(
     _CONF_UNIT_SYSTEM_METRIC,
     accumulated_precipitation=PRECIPITATION_MILLIMETERS,
+    conversions={
+        # Convert non-metric distances
+        ("distance", LENGTH_FEET): LENGTH_METERS,
+        ("distance", LENGTH_INCHES): LENGTH_MILLIMETERS,
+        ("distance", LENGTH_MILES): LENGTH_KILOMETERS,
+        ("distance", LENGTH_YARD): LENGTH_METERS,
+    },
     length=LENGTH_KILOMETERS,
-    length_conversions={LENGTH_MILES: LENGTH_KILOMETERS},
     mass=MASS_GRAMS,
     pressure=PRESSURE_PA,
     temperature=TEMP_CELSIUS,
@@ -271,8 +280,14 @@ METRIC_SYSTEM = UnitSystem(
 US_CUSTOMARY_SYSTEM = UnitSystem(
     _CONF_UNIT_SYSTEM_US_CUSTOMARY,
     accumulated_precipitation=PRECIPITATION_INCHES,
+    conversions={
+        # Convert non-USCS distances
+        ("distance", LENGTH_CENTIMETERS): LENGTH_INCHES,
+        ("distance", LENGTH_KILOMETERS): LENGTH_MILES,
+        ("distance", LENGTH_METERS): LENGTH_FEET,
+        ("distance", LENGTH_MILLIMETERS): LENGTH_INCHES,
+    },
     length=LENGTH_MILES,
-    length_conversions={LENGTH_KILOMETERS: LENGTH_MILES},
     mass=MASS_POUNDS,
     pressure=PRESSURE_PSI,
     temperature=TEMP_FAHRENHEIT,

tests/helpers/test_template.py

@@ -44,8 +44,8 @@ def _set_up_units(hass):
     hass.config.units = UnitSystem(
         "custom",
         accumulated_precipitation=LENGTH_MILLIMETERS,
+        conversions={},
         length=LENGTH_METERS,
-        length_conversions={},
         mass=MASS_GRAMS,
         pressure=PRESSURE_PA,
         temperature=TEMP_CELSIUS,

tests/util/test_unit_system.py

@@ -4,9 +4,14 @@ import pytest
 from homeassistant.const import (
     ACCUMULATED_PRECIPITATION,
     LENGTH,
+    LENGTH_CENTIMETERS,
+    LENGTH_FEET,
+    LENGTH_INCHES,
     LENGTH_KILOMETERS,
     LENGTH_METERS,
+    LENGTH_MILES,
     LENGTH_MILLIMETERS,
+    LENGTH_YARD,
     MASS,
     MASS_GRAMS,
     PRESSURE,
@@ -40,8 +45,8 @@ def test_invalid_units():
         UnitSystem(
             SYSTEM_NAME,
             accumulated_precipitation=LENGTH_MILLIMETERS,
+            conversions={},
             length=LENGTH_METERS,
-            length_conversions={},
             mass=MASS_GRAMS,
             pressure=PRESSURE_PA,
             temperature=INVALID_UNIT,
@@ -53,8 +58,8 @@ def test_invalid_units():
         UnitSystem(
             SYSTEM_NAME,
             accumulated_precipitation=LENGTH_MILLIMETERS,
+            conversions={},
             length=INVALID_UNIT,
-            length_conversions={},
             mass=MASS_GRAMS,
             pressure=PRESSURE_PA,
             temperature=TEMP_CELSIUS,
@@ -66,8 +71,8 @@ def test_invalid_units():
         UnitSystem(
             SYSTEM_NAME,
             accumulated_precipitation=LENGTH_MILLIMETERS,
+            conversions={},
             length=LENGTH_METERS,
-            length_conversions={},
             mass=MASS_GRAMS,
             pressure=PRESSURE_PA,
             temperature=TEMP_CELSIUS,
@@ -79,8 +84,8 @@ def test_invalid_units():
         UnitSystem(
             SYSTEM_NAME,
             accumulated_precipitation=LENGTH_MILLIMETERS,
+            conversions={},
             length=LENGTH_METERS,
-            length_conversions={},
             mass=MASS_GRAMS,
             pressure=PRESSURE_PA,
             temperature=TEMP_CELSIUS,
@@ -92,8 +97,8 @@ def test_invalid_units():
         UnitSystem(
             SYSTEM_NAME,
             accumulated_precipitation=LENGTH_MILLIMETERS,
+            conversions={},
             length=LENGTH_METERS,
-            length_conversions={},
             mass=INVALID_UNIT,
             pressure=PRESSURE_PA,
             temperature=TEMP_CELSIUS,
@@ -105,8 +110,8 @@ def test_invalid_units():
         UnitSystem(
             SYSTEM_NAME,
             accumulated_precipitation=LENGTH_MILLIMETERS,
+            conversions={},
             length=LENGTH_METERS,
-            length_conversions={},
             mass=MASS_GRAMS,
             pressure=INVALID_UNIT,
             temperature=TEMP_CELSIUS,
@@ -118,8 +123,8 @@ def test_invalid_units():
         UnitSystem(
             SYSTEM_NAME,
             accumulated_precipitation=INVALID_UNIT,
+            conversions={},
             length=LENGTH_METERS,
-            length_conversions={},
             mass=MASS_GRAMS,
             pressure=PRESSURE_PA,
             temperature=TEMP_CELSIUS,
@@ -374,3 +379,27 @@ def test_get_unit_system_invalid(key: str) -> None:
     """Test get_unit_system with an invalid key."""
     with pytest.raises(ValueError, match=f"`{key}` is not a valid unit system key"):
         _ = get_unit_system(key)
+
+
+@pytest.mark.parametrize(
+    "unit_system, device_class, original_unit, state_unit",
+    (
+        (METRIC_SYSTEM, "distance", LENGTH_FEET, LENGTH_METERS),
+        (METRIC_SYSTEM, "distance", LENGTH_INCHES, LENGTH_MILLIMETERS),
+        (METRIC_SYSTEM, "distance", LENGTH_MILES, LENGTH_KILOMETERS),
+        (METRIC_SYSTEM, "distance", LENGTH_YARD, LENGTH_METERS),
+        (METRIC_SYSTEM, "distance", LENGTH_KILOMETERS, None),
+        (METRIC_SYSTEM, "distance", "very_long", None),
+        (US_CUSTOMARY_SYSTEM, "distance", LENGTH_CENTIMETERS, LENGTH_INCHES),
+        (US_CUSTOMARY_SYSTEM, "distance", LENGTH_KILOMETERS, LENGTH_MILES),
+        (US_CUSTOMARY_SYSTEM, "distance", LENGTH_METERS, LENGTH_FEET),
+        (US_CUSTOMARY_SYSTEM, "distance", LENGTH_MILLIMETERS, LENGTH_INCHES),
+        (US_CUSTOMARY_SYSTEM, "distance", LENGTH_MILES, None),
+        (US_CUSTOMARY_SYSTEM, "distance", "very_long", None),
+    ),
+)
+def test_get_converted_unit(
+    unit_system, device_class, original_unit, state_unit
+) -> None:
+    """Test unit conversion rules."""
+    assert unit_system.get_converted_unit(device_class, original_unit) == state_unit