test: cover dhtcluster interface address selection

Co-authored-by: aberaud <101827+aberaud@users.noreply.github.com>

python/tests/dhtcluster_tests.py

@@ -0,0 +1,35 @@
+import runpy
+import unittest
+from pathlib import Path
+from unittest.mock import Mock, patch
+
+import netifaces
+
+
+class NodeClusterTester(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        script = Path(__file__).resolve().parents[1] / 'tools' / 'dhtcluster.py'
+        with patch.dict('sys.modules', {'opendht': Mock()}):
+            cls.NodeCluster = runpy.run_path(str(script))['NodeCluster']
+
+    def test_find_ip_interface(self):
+        addresses = {
+            netifaces.AF_INET: [{'addr': '127.0.0.1'}],
+            netifaces.AF_INET6: [{'addr': '::1'}],
+        }
+        with patch('netifaces.ifaddresses', return_value=addresses) as ifaddresses:
+            self.assertEqual(self.NodeCluster.find_ip('lo'), ('127.0.0.1', '::1'))
+        self.assertTrue(ifaddresses.called)
+        self.assertTrue(all(call.args == ('lo',) for call in ifaddresses.call_args_list))
+
+    def test_find_ip_any(self):
+        with patch('netifaces.ifaddresses') as ifaddresses:
+            for iface in (None, '', 'any'):
+                with self.subTest(iface=iface):
+                    self.assertEqual(self.NodeCluster.find_ip(iface), ('0.0.0.0', '::0'))
+        ifaddresses.assert_not_called()
+
+
+if __name__ == '__main__':
+    unittest.main()