fix: handle AuthError while probing for adapters

pyproject.toml

@@ -57,6 +57,11 @@ build_command = "pip install poetry && poetry build"
 [tool.pytest.ini_options]
 addopts = "-v -Wdefault --cov=bluetooth_adapters --cov-report=term-missing:skip-covered"
 pythonpath = ["src"]
+log_format = "%(asctime)s.%(msecs)03d %(levelname)-8s %(threadName)s %(name)s:%(filename)s:%(lineno)s %(message)s"
+log_date_format = "%Y-%m-%d %H:%M:%S"
+asyncio_mode = "auto"
+log_cli = "true"
+log_level = "NOTSET"
 
 [tool.coverage.run]
 branch = true

src/bluetooth_adapters/dbus.py

@@ -7,10 +7,11 @@
 from typing import Any
 
 try:
-    from dbus_fast import BusType, Message, MessageType, unpack_variants
+    from dbus_fast import AuthError, BusType, Message, MessageType, unpack_variants
     from dbus_fast.aio import MessageBus
 except (AttributeError, ImportError):
     # dbus_fast is not available on Windows
+    AuthError = None
     BusType = None
     Message = None
     MessageType = None
@@ -101,6 +102,13 @@ async def get_dbus_managed_objects() -> dict[str, Any]:
 async def _get_dbus_managed_objects() -> dict[str, Any]:
     try:
         bus = await MessageBus(bus_type=BusType.SYSTEM).connect()
+    except AuthError as ex:
+        _LOGGER.debug(
+            "DBus authentication error; make sure the DBus socket "
+            "is available and the user has the correct permissions: %s",
+            ex,
+        )
+        return {}
     except FileNotFoundError as ex:
         if is_docker_env():
             _LOGGER.debug(

tests/test_init.py

@@ -9,9 +9,10 @@
 from bleak.backends.scanner import AdvertisementData
 
 try:
-    from dbus_fast import MessageType
+    from dbus_fast import AuthError, MessageType
 except (AttributeError, ImportError):
     MessageType = None
+    AuthError = None
     # dbus_fast is not available on Windows
 from uart_devices import BluetoothDevice as UARTBluetoothDevice
 from uart_devices import UARTDevice
@@ -80,6 +81,22 @@ def __init__(self, *args, **kwargs):
         assert await get_bluetooth_adapters() == []
 
 
+@pytest.mark.asyncio
+@pytest.mark.skipif(
+    MessageType is None or get_dbus_managed_objects is None,
+    reason="dbus_fast is not available",
+)
+async def test_get_bluetooth_adapters_auth_eror():
+    """Test get_bluetooth_adapters with auth error."""
+
+    class MockMessageBus:
+        def __init__(self, *args, **kwargs):
+            raise AuthError
+
+    with patch("bluetooth_adapters.dbus.MessageBus", MockMessageBus):
+        assert await get_bluetooth_adapters() == []
+
+
 @pytest.mark.asyncio
 @pytest.mark.skipif(
     MessageType is None or get_dbus_managed_objects is None,