thermalctld: fix test warnings

sonic-thermalctld/tests/mocked_libs/swsscommon/swsscommon.py

@@ -5,6 +5,7 @@
 from swsssdk import ConfigDBConnector, SonicDBConfig, SonicV2Connector
 
 STATE_DB = ''
+CHASSIS_STATE_DB = ''
 
 
 class Table:
@@ -28,6 +29,9 @@ def get(self, key):
     def get_size(self):
         return (len(self.mock_dict))
 
+    def getKeys(self):
+        return list(self.mock_dict.keys())
+
 
 class FieldValuePairs:
     fv_dict = {}

sonic-thermalctld/tests/test_thermalctld.py

@@ -1,13 +1,11 @@
 import os
 import sys
 import multiprocessing
-from imp import load_source  # TODO: Replace with importlib once we no longer need to support Python 2
+import importlib.machinery
+import importlib.util
+
+from unittest import mock
 
-# TODO: Clean this up once we no longer need to support Python 2
-if sys.version_info.major == 3:
-    from unittest import mock
-else:
-    import mock
 
 import pytest
 tests_path = os.path.dirname(os.path.abspath(__file__))
@@ -25,7 +23,10 @@
 from sonic_py_common import daemon_base
 
 from .mock_platform import MockChassis, MockFan, MockModule, MockPsu, MockSfp, MockThermal
-from .mock_swsscommon import Table
+from .mocked_libs.swsscommon import swsscommon
+
+Table = swsscommon.Table
+FieldValuePairs = swsscommon.FieldValuePairs
 
 daemon_base.db_connect = mock.MagicMock()
 
@@ -34,6 +35,16 @@
 scripts_path = os.path.join(modules_path, 'scripts')
 sys.path.insert(0, modules_path)
 
+# Replacement for imp.load_source from the Python3.12 docs:
+#   https://docs.python.org/3/whatsnew/3.12.html#imp
+def load_source(modname, filename):
+    loader = importlib.machinery.SourceFileLoader(modname, filename)
+    spec = importlib.util.spec_from_file_location(modname, filename, loader=loader)
+    module = importlib.util.module_from_spec(spec)
+    sys.modules[module.__name__] = module
+    loader.exec_module(module)
+    return module
+
 load_source('thermalctld', os.path.join(scripts_path, 'thermalctld'))
 import thermalctld