style: Fix linting errors and follow test file conventions

- Move imports to top level (mock, UNIX_SOCKET_PATHS, _find_available_unix_socket)
- Remove unused imports inside test methods
- Format mock.patch calls to follow line length conventions

Author: halicki

tests/unit/utils_test.py

@@ -5,11 +5,17 @@
 import shutil
 import tempfile
 import unittest
+from unittest import mock
 
 import pytest
 
 from docker.api.client import APIClient
-from docker.constants import DEFAULT_DOCKER_API_VERSION, IS_WINDOWS_PLATFORM
+from docker.constants import (
+    DEFAULT_DOCKER_API_VERSION,
+    IS_WINDOWS_PLATFORM,
+    UNIX_SOCKET_PATHS,
+)
+from docker.constants import _find_available_unix_socket
 from docker.errors import DockerException
 from docker.utils import (
     compare_version,
@@ -641,82 +647,71 @@ class UnixSocketDiscoveryTest(unittest.TestCase):
 
     def test_find_socket_prefers_traditional_location(self):
         """When /var/run/docker.sock exists, it should be preferred."""
-        from unittest import mock
-        from docker.constants import UNIX_SOCKET_PATHS, _find_available_unix_socket
 
         def mock_exists(path):
             # All sockets exist - should prefer the first one
             return path in UNIX_SOCKET_PATHS
 
-        with mock.patch('docker.constants.os.path.exists', side_effect=mock_exists):
+        with mock.patch("docker.constants.os.path.exists", side_effect=mock_exists):
             result = _find_available_unix_socket()
             assert result == "http+unix:///var/run/docker.sock"
 
     def test_find_socket_falls_back_to_docker_desktop(self):
         """When only ~/.docker/run/docker.sock exists, it should be used."""
-        from unittest import mock
-        from docker.constants import UNIX_SOCKET_PATHS, _find_available_unix_socket
-
-        docker_desktop_socket = os.path.expanduser('~/.docker/run/docker.sock')
+        docker_desktop_socket = os.path.expanduser("~/.docker/run/docker.sock")
 
         def mock_exists(path):
             # Only Docker Desktop v4.x+ socket exists
             return path == docker_desktop_socket
 
-        with mock.patch('docker.constants.os.path.exists', side_effect=mock_exists):
+        with mock.patch("docker.constants.os.path.exists", side_effect=mock_exists):
             result = _find_available_unix_socket()
             assert result == f"http+unix://{docker_desktop_socket}"
 
     def test_find_socket_falls_back_to_older_docker_desktop(self):
         """When only ~/.docker/desktop/docker.sock exists, it should be used."""
-        from unittest import mock
-        from docker.constants import UNIX_SOCKET_PATHS, _find_available_unix_socket
-
-        older_desktop_socket = os.path.expanduser('~/.docker/desktop/docker.sock')
+        older_desktop_socket = os.path.expanduser("~/.docker/desktop/docker.sock")
 
         def mock_exists(path):
             # Only older Docker Desktop socket exists
             return path == older_desktop_socket
 
-        with mock.patch('docker.constants.os.path.exists', side_effect=mock_exists):
+        with mock.patch("docker.constants.os.path.exists", side_effect=mock_exists):
             result = _find_available_unix_socket()
             assert result == f"http+unix://{older_desktop_socket}"
 
     def test_find_socket_fallback_when_none_exist(self):
         """When no socket exists, should fall back to traditional location."""
-        from unittest import mock
-        from docker.constants import _find_available_unix_socket
 
         def mock_exists(path):
             # No sockets exist
             return False
 
-        with mock.patch('docker.constants.os.path.exists', side_effect=mock_exists):
+        with mock.patch("docker.constants.os.path.exists", side_effect=mock_exists):
             result = _find_available_unix_socket()
             # Should fall back to traditional location for consistent error messages
             assert result == "http+unix:///var/run/docker.sock"
 
     def test_find_socket_preference_order(self):
         """Verify the preference order: traditional > docker desktop v4 > older desktop."""
-        from unittest import mock
-        from docker.constants import UNIX_SOCKET_PATHS, _find_available_unix_socket
-
-        docker_desktop_socket = os.path.expanduser('~/.docker/run/docker.sock')
-        older_desktop_socket = os.path.expanduser('~/.docker/desktop/docker.sock')
+        docker_desktop_socket = os.path.expanduser("~/.docker/run/docker.sock")
+        older_desktop_socket = os.path.expanduser("~/.docker/desktop/docker.sock")
 
         # Test: when docker desktop v4 and older both exist, v4 should win
         def mock_exists_v4_and_older(path):
             return path in [docker_desktop_socket, older_desktop_socket]
 
-        with mock.patch('docker.constants.os.path.exists', side_effect=mock_exists_v4_and_older):
+        with mock.patch(
+            "docker.constants.os.path.exists", side_effect=mock_exists_v4_and_older
+        ):
             result = _find_available_unix_socket()
             assert result == f"http+unix://{docker_desktop_socket}"
 
     def test_unix_socket_paths_order(self):
         """Verify UNIX_SOCKET_PATHS contains expected paths in correct order."""
-        from docker.constants import UNIX_SOCKET_PATHS
-
         assert len(UNIX_SOCKET_PATHS) == 3
-        assert UNIX_SOCKET_PATHS[0] == '/var/run/docker.sock'
-        assert UNIX_SOCKET_PATHS[1] == os.path.expanduser('~/.docker/run/docker.sock')
-        assert UNIX_SOCKET_PATHS[2] == os.path.expanduser('~/.docker/desktop/docker.sock')
+        assert UNIX_SOCKET_PATHS[0] == "/var/run/docker.sock"
+        assert UNIX_SOCKET_PATHS[1] == os.path.expanduser("~/.docker/run/docker.sock")
+        assert UNIX_SOCKET_PATHS[2] == os.path.expanduser(
+            "~/.docker/desktop/docker.sock"
+        )