From 6a757662e47061dcd99faf4f16881784ed2e2d89 Mon Sep 17 00:00:00 2001
From: epenet <6771947+epenet@users.noreply.github.com>
Date: Fri, 14 Oct 2022 13:44:18 +0200
Subject: [PATCH] Deprecate is_metric property of unit system (#80313)

---
 homeassistant/util/unit_system.py |  8 +++++++-
 tests/util/test_unit_system.py    | 18 +++++++++++++++---
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/homeassistant/util/unit_system.py b/homeassistant/util/unit_system.py
index 347c8ae859b..5c1f6d647a1 100644
--- a/homeassistant/util/unit_system.py
+++ b/homeassistant/util/unit_system.py
@@ -131,7 +131,13 @@ class UnitSystem:
     @property
     def is_metric(self) -> bool:
         """Determine if this is the metric unit system."""
-        return self._name == CONF_UNIT_SYSTEM_METRIC
+        report(
+            "accesses the `is_metric` property of the unit system. "
+            "This is deprecated and will stop working in Home Assistant 2023.1. "
+            "Please adjust to use instance check instead.",
+            error_if_core=False,
+        )
+        return self is METRIC_SYSTEM
 
     def temperature(self, temperature: float, from_unit: str) -> float:
         """Convert the given temperature to this unit system."""
diff --git a/tests/util/test_unit_system.py b/tests/util/test_unit_system.py
index 72a4456a219..8c7a9cf2fc5 100644
--- a/tests/util/test_unit_system.py
+++ b/tests/util/test_unit_system.py
@@ -296,10 +296,22 @@ def test_properties():
     assert METRIC_SYSTEM.accumulated_precipitation_unit == LENGTH_MILLIMETERS
 
 
-def test_is_metric():
+@pytest.mark.parametrize(
+    "unit_system, expected_flag",
+    [
+        (METRIC_SYSTEM, True),
+        (IMPERIAL_SYSTEM, False),
+    ],
+)
+def test_is_metric(
+    caplog: pytest.LogCaptureFixture, unit_system: UnitSystem, expected_flag: bool
+):
     """Test the is metric flag."""
-    assert METRIC_SYSTEM.is_metric
-    assert not IMPERIAL_SYSTEM.is_metric
+    assert unit_system.is_metric == expected_flag
+    assert (
+        "Detected code that accesses the `is_metric` property of the unit system."
+        in caplog.text
+    )
 
 
 @pytest.mark.parametrize(