test: add unit tests for endpoint tls_session_cache_key

Add tests verifying the tls_session_cache_key property for each
endpoint type:
- DefaultEndPoint returns (address, port)
- SniEndPoint includes server_name to prevent cache collisions
- UnixSocketEndPoint returns just the path

Author: dkropachev

tests/unit/test_endpoints.py

@@ -10,7 +10,7 @@
 
 import itertools
 
-from cassandra.connection import DefaultEndPoint, SniEndPoint, SniEndPointFactory
+from cassandra.connection import DefaultEndPoint, SniEndPoint, SniEndPointFactory, UnixSocketEndPoint
 
 from unittest.mock import patch
 
@@ -53,3 +53,41 @@ def test_endpoint_resolve(self):
         for i in range(10):
             (address, _) = endpoint.resolve()
             assert address == next(it)
+
+    def test_sni_endpoint_tls_session_cache_key(self):
+        """Test that SNI endpoints include server_name in cache key."""
+        endpoint1 = self.endpoint_factory.create_from_sni('server1.example.com')
+        endpoint2 = self.endpoint_factory.create_from_sni('server2.example.com')
+
+        # Both have same proxy address and port
+        assert endpoint1.address == endpoint2.address
+        assert endpoint1.port == endpoint2.port
+
+        # But different cache keys due to server_name
+        assert endpoint1.tls_session_cache_key != endpoint2.tls_session_cache_key
+        assert endpoint1.tls_session_cache_key == ('proxy.datastax.com', 30002, 'server1.example.com')
+        assert endpoint2.tls_session_cache_key == ('proxy.datastax.com', 30002, 'server2.example.com')
+
+
+class DefaultEndPointTest(unittest.TestCase):
+
+    def test_tls_session_cache_key(self):
+        """Test that DefaultEndPoint cache key is (address, port)."""
+        endpoint = DefaultEndPoint('10.0.0.1', 9042)
+        assert endpoint.tls_session_cache_key == ('10.0.0.1', 9042)
+
+        endpoint2 = DefaultEndPoint('10.0.0.1', 9043)
+        assert endpoint2.tls_session_cache_key == ('10.0.0.1', 9043)
+        assert endpoint.tls_session_cache_key != endpoint2.tls_session_cache_key
+
+
+class UnixSocketEndPointTest(unittest.TestCase):
+
+    def test_tls_session_cache_key(self):
+        """Test that UnixSocketEndPoint cache key is just the path."""
+        endpoint = UnixSocketEndPoint('/var/run/scylla.sock')
+        assert endpoint.tls_session_cache_key == ('/var/run/scylla.sock',)
+
+        # Different paths should have different keys
+        endpoint2 = UnixSocketEndPoint('/tmp/scylla.sock')
+        assert endpoint.tls_session_cache_key != endpoint2.tls_session_cache_key