新增pod_bridge吊舱桥接中间件(树莓派4B部署)

- pod_bridge: 协议G版编解码/地理位置引导律/PX4网关/串口链路/闭环主循环
- 含三项安全修复: position_time_ms拆分、表2-2锁定门控、run()异常护栏
- 测试92条全绿; 附树莓派4B(Ubuntu 24.04)部署注意事项与最小依赖清单

utils/tests/pod_bridge/pod_serial_test.py

@@ -0,0 +1,89 @@
+"""pod_serial_test.py —— PodSerial 单元测试（注入 fake serial 模块，无硬件）。"""
+
+import sys
+import types
+
+import pytest
+
+from pod_bridge.pod_serial import PodLink, PodSerial
+from pod_bridge.protocol import TargetGeo, encode_target
+
+
+class _FakeSerialInstance:
+    def __init__(self, **kwargs):
+        self.kwargs = kwargs
+        self._buf = b""
+        self.written = []
+        self.closed = False
+
+    @property
+    def in_waiting(self):
+        return len(self._buf)
+
+    def read(self, n):
+        data, self._buf = self._buf[:n], self._buf[n:]
+        return data
+
+    def write(self, data):
+        self.written.append(data)
+
+    def close(self):
+        self.closed = True
+
+
+@pytest.fixture
+def fake_serial(monkeypatch):
+    mod = types.ModuleType("serial")
+    mod.EIGHTBITS = 8
+    mod.PARITY_NONE = "N"
+    mod.STOPBITS_ONE = 1
+    mod.Serial = _FakeSerialInstance
+    monkeypatch.setitem(sys.modules, "serial", mod)
+    return mod
+
+
+def test_empty_port_raises():
+    with pytest.raises(ValueError, match="port 为空"):
+        PodSerial("")
+
+
+def test_serial_opened_with_8n1(fake_serial):
+    ps = PodSerial("COM3", baudrate=115200)
+    kw = ps._ser.kwargs
+    assert kw["port"] == "COM3"
+    assert kw["baudrate"] == 115200
+    assert kw["bytesize"] == 8
+    assert kw["parity"] == "N"
+    assert kw["stopbits"] == 1
+    assert kw["timeout"] == 0  # 非阻塞轮询
+
+
+def test_poll_parses_buffered_frames(fake_serial):
+    ps = PodSerial("COM3")
+    ps._ser._buf = encode_target(TargetGeo(latitude_deg=31.0, longitude_deg=121.0))
+    frames = ps.poll()
+    assert len(frames) == 1
+    assert isinstance(frames[0], TargetGeo)
+    assert frames[0].latitude_deg == pytest.approx(31.0, abs=1e-7)
+
+
+def test_poll_empty_returns_empty_list(fake_serial):
+    ps = PodSerial("COM3")
+    assert ps.poll() == []
+
+
+def test_send_writes_bytes(fake_serial):
+    ps = PodSerial("COM3")
+    ps.send(b"\xeb\x90\x01")
+    assert ps._ser.written == [b"\xeb\x90\x01"]
+
+
+def test_close_closes_serial(fake_serial):
+    ps = PodSerial("COM3")
+    ps.close()
+    assert ps._ser.closed is True
+
+
+def test_satisfies_podlink_protocol(fake_serial):
+    ps = PodSerial("COM3")
+    assert isinstance(ps, PodLink)