Fix agent runner steering and lifecycle hardening

tests/unit_tests/pipeline/test_controller.py

@@ -0,0 +1,63 @@
+from __future__ import annotations
+
+from types import SimpleNamespace
+from unittest.mock import AsyncMock, MagicMock
+
+import pytest
+
+from langbot.pkg.agent.runner.errors import RunnerNotFoundError
+from langbot.pkg.pipeline.controller import Controller
+
+
+def make_app():
+    app = SimpleNamespace()
+    app.instance_config = SimpleNamespace(data={'concurrency': {'pipeline': 10}})
+    app.logger = MagicMock()
+    app.pipeline_mgr = SimpleNamespace()
+    app.pipeline_mgr.get_pipeline_by_uuid = AsyncMock()
+    app.sess_mgr = SimpleNamespace()
+    app.sess_mgr.get_session = AsyncMock(return_value=SimpleNamespace())
+    app.agent_run_orchestrator = SimpleNamespace()
+    app.agent_run_orchestrator.try_claim_steering_from_query = AsyncMock()
+    return app
+
+
+def make_pipeline():
+    return SimpleNamespace(
+        pipeline_entity=SimpleNamespace(config={'ai': {'runner': {'id': 'plugin:test/runner/default'}}}),
+        bound_plugins=['test/runner'],
+        bound_mcp_servers=[],
+    )
+
+
+@pytest.mark.asyncio
+async def test_try_claim_steering_returns_false_when_runner_lookup_fails():
+    app = make_app()
+    app.pipeline_mgr.get_pipeline_by_uuid.return_value = make_pipeline()
+    app.agent_run_orchestrator.try_claim_steering_from_query.side_effect = RunnerNotFoundError(
+        'plugin:missing/runner/default'
+    )
+    controller = Controller(app)
+    query = SimpleNamespace(query_id=1, pipeline_uuid='pipeline-001', variables={})
+
+    claimed = await controller._try_claim_steering_before_session_slot(query)
+
+    assert claimed is False
+    app.logger.warning.assert_called_once()
+
+
+@pytest.mark.asyncio
+async def test_try_claim_steering_sets_pipeline_context_before_claiming():
+    app = make_app()
+    pipeline = make_pipeline()
+    app.pipeline_mgr.get_pipeline_by_uuid.return_value = pipeline
+    app.agent_run_orchestrator.try_claim_steering_from_query.return_value = True
+    controller = Controller(app)
+    query = SimpleNamespace(query_id=2, pipeline_uuid='pipeline-002', variables={})
+
+    claimed = await controller._try_claim_steering_before_session_slot(query)
+
+    assert claimed is True
+    assert query.pipeline_config is pipeline.pipeline_entity.config
+    assert query.variables['_pipeline_bound_plugins'] == ['test/runner']
+    app.agent_run_orchestrator.try_claim_steering_from_query.assert_awaited_once_with(query)