add py 310 threadpoolsetting tests (#996)

* add py 310 threadpoolsetting tests


Co-authored-by: peterstone2017 <yunchuwang5@gmail.com>

tests/unittests/test_dispatcher.py

@@ -489,3 +489,30 @@ def tearDown(self):
         os.environ.update(self._pre_env)
         self.mock_os_cpu.stop()
         self.mock_version_info.stop()
+
+
+@unittest.skipIf(sys.version_info.minor != 10,
+                 "Run the tests only for Python 3.10. In other platforms, "
+                 "as the default passed is None, the cpu_count determines the "
+                 "number of max_workers and we cannot mock the os.cpu_count() "
+                 "in the concurrent.futures.ThreadPoolExecutor")
+class TestThreadPoolSettingsPython310(TestThreadPoolSettingsPython39):
+    def setUp(self):
+        super(TestThreadPoolSettingsPython310, self).setUp()
+
+        self.mock_os_cpu = patch(
+            'os.cpu_count', return_value=2)
+        # 6 - based on 2 cores - min(32, (os.cpu_count() or 1) + 4) - 2 + 4
+        self._default_workers: Optional[int] = 6
+        self.mock_version_info = patch(
+            'azure_functions_worker.dispatcher.sys.version_info',
+            SysVersionInfo(3, 10, 0, 'final', 0))
+
+        self.mock_os_cpu.start()
+        self.mock_version_info.start()
+
+    def tearDown(self):
+        os.environ.clear()
+        os.environ.update(self._pre_env)
+        self.mock_os_cpu.stop()
+        self.mock_version_info.stop()