fix(amber): avoids false negative on _check_heartbeat when connection is established but close raises exception

amber/src/main/python/core/runnables/heartbeat.py

@@ -79,22 +79,26 @@ def run(self) -> None:
 
     def _check_heartbeat(self) -> bool:
         """
-        Attempt to connect to JVM on the specific port. If succeeds, it means the
-        socket is still available and the JVM is still alive. Otherwise, the JVM
-        might have been gone.
+        Attempt to connect to the JVM port. Returns True iff socket.create_connection succeeds;
+        a close() failure after a successful connection is logged but DOES NOT flip the return value.
 
-        :return: bool, indicating if the socket is available.
+        :return: bool, True if connect succeeded, False if connect failed.
         """
         try:
             temp_socket = socket.create_connection(
                 (self._parsed_server_host, self._parsed_server_port), timeout=1
             )
-            temp_socket.close()
-            return True
         except Exception as e:
             logger.warning(f"Server is down with exception: {e}")
             return False
 
+        try:
+            temp_socket.close()
+        except Exception as e:
+            logger.warning(f"Failed to close socket: {e}")
+
+        return True
+
     @overrides
     def stop(self):
         # clean up every process under the python worker

amber/src/test/python/core/runnables/test_heartbeat.py

@@ -79,20 +79,16 @@ def test_returns_false_when_socket_connection_times_out(self):
         ):
             assert hb._check_heartbeat() is False
 
-    def test_returns_false_when_socket_close_raises(self):
-        # Pins the false-negative path: connect succeeds but the subsequent
-        # close() throws (e.g. broken pipe on a half-open socket). The bare
-        # `except Exception` in _check_heartbeat() catches it and reports
-        # "server down", and a regression that narrows that handler would be
-        # caught here.
+    def test_returns_true_when_connection_succeeds_but_socket_close_raises(self):
         hb = make_heartbeat()
         fake_sock = MagicMock()
         fake_sock.close.side_effect = OSError("close failed")
         with patch(
             "core.runnables.heartbeat.socket.create_connection",
             return_value=fake_sock,
         ):
-            assert hb._check_heartbeat() is False
+            assert hb._check_heartbeat() is True
+            fake_sock.close.assert_called_once()
 
 
 class TestRunEarlyExit: