feat(graph-engine): make layer runtime state non-null and bound early (#30552)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

api/tests/test_containers_integration_tests/core/app/layers/test_pause_state_persist_layer.py

@@ -35,6 +35,7 @@ from core.model_runtime.entities.llm_entities import LLMUsage
 from core.workflow.entities.pause_reason import SchedulingPause
 from core.workflow.enums import WorkflowExecutionStatus
 from core.workflow.graph_engine.entities.commands import GraphEngineCommand
+from core.workflow.graph_engine.layers.base import GraphEngineLayerNotInitializedError
 from core.workflow.graph_events.graph import GraphRunPausedEvent
 from core.workflow.runtime.graph_runtime_state import GraphRuntimeState
 from core.workflow.runtime.graph_runtime_state_protocol import ReadOnlyGraphRuntimeState
@@ -569,10 +570,10 @@ class TestPauseStatePersistenceLayerTestContainers:
         """Test that layer requires proper initialization before handling events."""
         # Arrange
         layer = self._create_pause_state_persistence_layer()
-        # Don't initialize - graph_runtime_state should not be set
+        # Don't initialize - graph_runtime_state should be uninitialized
 
         event = GraphRunPausedEvent(reasons=[SchedulingPause(message="test pause")])
 
-        # Act & Assert - Should raise AttributeError
-        with pytest.raises(AttributeError):
+        # Act & Assert - Should raise GraphEngineLayerNotInitializedError
+        with pytest.raises(GraphEngineLayerNotInitializedError):
             layer.on_event(event)

api/tests/unit_tests/core/app/layers/test_pause_state_persist_layer.py

@@ -15,6 +15,7 @@ from core.app.layers.pause_state_persist_layer import (
 from core.variables.segments import Segment
 from core.workflow.entities.pause_reason import SchedulingPause
 from core.workflow.graph_engine.entities.commands import GraphEngineCommand
+from core.workflow.graph_engine.layers.base import GraphEngineLayerNotInitializedError
 from core.workflow.graph_events.graph import (
     GraphRunFailedEvent,
     GraphRunPausedEvent,
@@ -209,8 +210,9 @@ class TestPauseStatePersistenceLayer:
 
         assert layer._session_maker is session_factory
         assert layer._state_owner_user_id == state_owner_user_id
-        assert not hasattr(layer, "graph_runtime_state")
-        assert not hasattr(layer, "command_channel")
+        with pytest.raises(GraphEngineLayerNotInitializedError):
+            _ = layer.graph_runtime_state
+        assert layer.command_channel is None
 
     def test_initialize_sets_dependencies(self):
         session_factory = Mock(name="session_factory")
@@ -295,7 +297,7 @@ class TestPauseStatePersistenceLayer:
         mock_factory.assert_not_called()
         mock_repo.create_workflow_pause.assert_not_called()
 
-    def test_on_event_raises_attribute_error_when_graph_runtime_state_is_none(self):
+    def test_on_event_raises_when_graph_runtime_state_is_uninitialized(self):
         session_factory = Mock(name="session_factory")
         layer = PauseStatePersistenceLayer(
             session_factory=session_factory,
@@ -305,7 +307,7 @@ class TestPauseStatePersistenceLayer:
 
         event = TestDataFactory.create_graph_run_paused_event()
 
-        with pytest.raises(AttributeError):
+        with pytest.raises(GraphEngineLayerNotInitializedError):
             layer.on_event(event)
 
     def test_on_event_asserts_when_workflow_execution_id_missing(self, monkeypatch: pytest.MonkeyPatch):

api/tests/unit_tests/core/workflow/graph_engine/layers/test_layer_initialization.py

@@ -0,0 +1,56 @@
+from __future__ import annotations
+
+import pytest
+
+from core.workflow.graph_engine import GraphEngine
+from core.workflow.graph_engine.command_channels import InMemoryChannel
+from core.workflow.graph_engine.layers.base import (
+    GraphEngineLayer,
+    GraphEngineLayerNotInitializedError,
+)
+from core.workflow.graph_events import GraphEngineEvent
+
+from ..test_table_runner import WorkflowRunner
+
+
+class LayerForTest(GraphEngineLayer):
+    def on_graph_start(self) -> None:
+        pass
+
+    def on_event(self, event: GraphEngineEvent) -> None:
+        pass
+
+    def on_graph_end(self, error: Exception | None) -> None:
+        pass
+
+
+def test_layer_runtime_state_raises_when_uninitialized() -> None:
+    layer = LayerForTest()
+
+    with pytest.raises(GraphEngineLayerNotInitializedError):
+        _ = layer.graph_runtime_state
+
+
+def test_layer_runtime_state_available_after_engine_layer() -> None:
+    runner = WorkflowRunner()
+    fixture_data = runner.load_fixture("simple_passthrough_workflow")
+    graph, graph_runtime_state = runner.create_graph_from_fixture(
+        fixture_data,
+        inputs={"query": "test layer state"},
+    )
+    engine = GraphEngine(
+        workflow_id="test_workflow",
+        graph=graph,
+        graph_runtime_state=graph_runtime_state,
+        command_channel=InMemoryChannel(),
+    )
+
+    layer = LayerForTest()
+    engine.layer(layer)
+
+    outputs = layer.graph_runtime_state.outputs
+    ready_queue_size = layer.graph_runtime_state.ready_queue_size
+
+    assert outputs == {}
+    assert isinstance(ready_queue_size, int)
+    assert ready_queue_size >= 0