fix(runtime): harden connector lifecycle

tests/unit_tests/plugin/test_connector_ping.py

@@ -1,15 +1,20 @@
 from __future__ import annotations
 
+import asyncio
 from types import SimpleNamespace
-from unittest.mock import AsyncMock
+from unittest.mock import AsyncMock, Mock
 
 import pytest
 
+from langbot.pkg.plugin import connector as connector_module
 from langbot.pkg.plugin.connector import PluginRuntimeConnector, PluginRuntimeNotConnectedError
 
 
 def make_connector() -> PluginRuntimeConnector:
-    app = SimpleNamespace(instance_config=SimpleNamespace(data={'plugin': {'enable': True}}))
+    app = SimpleNamespace(
+        logger=Mock(),
+        instance_config=SimpleNamespace(data={'plugin': {'enable': True}, 'space': {'url': ''}}),
+    )
     return PluginRuntimeConnector(app, AsyncMock())
 
 
@@ -30,3 +35,133 @@ async def test_ping_plugin_runtime_delegates_to_connected_handler():
 
     assert result == 'pong'
     connector.handler.ping.assert_awaited_once()
+
+
+@pytest.mark.asyncio
+async def test_stop_transport_tolerates_handler_callback_removing_attribute():
+    connector = make_connector()
+
+    class Handler:
+        async def close(self):
+            del connector.handler
+
+    connector.handler = Handler()
+
+    await connector._stop_transport()
+
+    assert not hasattr(connector, 'handler')
+
+
+@pytest.mark.asyncio
+async def test_stdio_runtime_connection_does_not_capture_unconsumed_stderr(
+    monkeypatch: pytest.MonkeyPatch,
+):
+    connector = make_connector()
+    created = {}
+
+    class FakeRuntimeHandler:
+        def __init__(self, connection, disconnect_callback, ap):
+            self.release = asyncio.Event()
+
+        async def ping(self):
+            return None
+
+        async def set_runtime_config(self, **kwargs):
+            return None
+
+        async def run(self):
+            await self.release.wait()
+
+        async def close(self):
+            self.release.set()
+
+    class FakeController:
+        def __init__(self, **kwargs):
+            created.update(kwargs)
+
+        async def run(self, callback):
+            await callback(object())
+
+        async def close(self):
+            return None
+
+    monkeypatch.setattr(connector_module.platform, 'get_platform', lambda: 'linux')
+    monkeypatch.setattr(
+        connector_module.platform,
+        'use_websocket_to_connect_plugin_runtime',
+        lambda: False,
+    )
+    monkeypatch.setattr(
+        connector_module.handler,
+        'RuntimeConnectionHandler',
+        FakeRuntimeHandler,
+    )
+    monkeypatch.setattr(
+        connector_module.stdio_client_controller,
+        'StdioClientController',
+        FakeController,
+    )
+
+    await connector.initialize()
+
+    assert created['capture_stderr'] is False
+    assert connector._connected.is_set()
+    await connector.aclose()
+
+
+@pytest.mark.asyncio
+async def test_runtime_disconnect_notifies_once_and_clears_handler(
+    monkeypatch: pytest.MonkeyPatch,
+):
+    disconnect = AsyncMock()
+    connector = PluginRuntimeConnector(make_connector().ap, disconnect)
+
+    class FakeRuntimeHandler:
+        def __init__(self, connection, disconnect_callback, ap):
+            self.disconnect_callback = disconnect_callback
+
+        async def ping(self):
+            return None
+
+        async def set_runtime_config(self, **kwargs):
+            return None
+
+        async def run(self):
+            await self.disconnect_callback(self)
+
+        async def close(self):
+            return None
+
+    class FakeController:
+        def __init__(self, **kwargs):
+            pass
+
+        async def run(self, callback):
+            await callback(object())
+
+        async def close(self):
+            return None
+
+    monkeypatch.setattr(connector_module.platform, 'get_platform', lambda: 'linux')
+    monkeypatch.setattr(
+        connector_module.platform,
+        'use_websocket_to_connect_plugin_runtime',
+        lambda: False,
+    )
+    monkeypatch.setattr(
+        connector_module.handler,
+        'RuntimeConnectionHandler',
+        FakeRuntimeHandler,
+    )
+    monkeypatch.setattr(
+        connector_module.stdio_client_controller,
+        'StdioClientController',
+        FakeController,
+    )
+
+    await connector.initialize()
+    await asyncio.sleep(0)
+
+    disconnect.assert_awaited_once_with(connector)
+    assert not hasattr(connector, 'handler')
+    await connector.aclose()