Fix transport and fund flow protocol edge cases

tests/unit/test_sync_transport.py

@@ -0,0 +1,44 @@
+"""同步 transport 回归测试。"""
+
+from unittest.mock import patch
+
+from xmtdx.exceptions import TdxConnectionError
+from xmtdx.transport.sync import TdxConnection
+
+
+class _FakeSocket:
+    def __init__(self) -> None:
+        self.timeout: float | None = None
+        self.connected_to: tuple[str, int] | None = None
+        self.closed = False
+
+    def settimeout(self, timeout: float) -> None:
+        self.timeout = timeout
+
+    def connect(self, address: tuple[str, int]) -> None:
+        self.connected_to = address
+
+    def close(self) -> None:
+        self.closed = True
+
+
+def test_sync_connection_closes_socket_when_setup_fails() -> None:
+    sock = _FakeSocket()
+    conn = TdxConnection("127.0.0.1", port=7709, timeout=0.2)
+
+    with patch("xmtdx.transport.sync.socket.socket", return_value=sock), patch.object(
+        TdxConnection,
+        "_send_setup",
+        side_effect=TdxConnectionError("setup failed"),
+    ):
+        try:
+            conn.connect()
+        except TdxConnectionError as exc:
+            assert "setup failed" in str(exc)
+        else:  # pragma: no cover - 防御性断言
+            raise AssertionError("expected setup failure")
+
+    assert sock.timeout == 0.2
+    assert sock.connected_to == ("127.0.0.1", 7709)
+    assert sock.closed is True
+    assert conn._sock is None