Add test

libs/langgraph/tests/test_pregel.py

@@ -14378,3 +14378,79 @@ def test_runnable_passthrough_node_graph() -> None:
     graph = graph_builder.compile()
 
     assert graph.get_graph(xray=True).to_json() == graph.get_graph(xray=False).to_json()
+
+
+@pytest.mark.parametrize("checkpointer_name", ALL_CHECKPOINTERS_SYNC)
+def test_parent_command(request: pytest.FixtureRequest, checkpointer_name: str) -> None:
+    from langchain_core.messages import BaseMessage
+    from langchain_core.tools import tool
+
+    @tool(return_direct=True)
+    def get_user_name() -> GraphCommand:
+        """Retrieve user name"""
+        return GraphCommand(update={"user_name": "Meow"}, graph=GraphCommand.PARENT)
+
+    subgraph_builder = StateGraph(MessagesState)
+    subgraph_builder.add_node("tool", get_user_name)
+    subgraph_builder.add_edge(START, "tool")
+    subgraph = subgraph_builder.compile()
+
+    class CustomParentState(TypedDict):
+        messages: Annotated[list[BaseMessage], add_messages]
+        # this key is not available to the child graph
+        user_name: str
+
+    builder = StateGraph(CustomParentState)
+    builder.add_node("alice", subgraph)
+    builder.add_edge(START, "alice")
+    checkpointer = request.getfixturevalue(f"checkpointer_{checkpointer_name}")
+    graph = builder.compile(checkpointer=checkpointer)
+
+    config = {"configurable": {"thread_id": "1"}}
+
+    assert graph.invoke({"messages": [("user", "get user name")]}, config) == {
+        "messages": [
+            _AnyIdHumanMessage(
+                content="get user name", additional_kwargs={}, response_metadata={}
+            ),
+        ],
+        "user_name": "Meow",
+    }
+    assert graph.get_state(config) == StateSnapshot(
+        values={
+            "messages": [
+                _AnyIdHumanMessage(
+                    content="get user name", additional_kwargs={}, response_metadata={}
+                ),
+            ],
+            "user_name": "Meow",
+        },
+        next=(),
+        config={
+            "configurable": {
+                "thread_id": "1",
+                "checkpoint_ns": "",
+                "checkpoint_id": AnyStr(),
+            }
+        },
+        metadata={
+            "source": "loop",
+            "writes": {
+                "alice": {
+                    "user_name": "Meow",
+                }
+            },
+            "thread_id": "1",
+            "step": 1,
+            "parents": {},
+        },
+        created_at=AnyStr(),
+        parent_config={
+            "configurable": {
+                "thread_id": "1",
+                "checkpoint_ns": "",
+                "checkpoint_id": AnyStr(),
+            }
+        },
+        tasks=(),
+    )

libs/langgraph/tests/test_pregel_async.py

@@ -12565,3 +12565,83 @@ async def test_debug_nested_subgraphs():
                 assert stream_task["interrupts"] == history_task.interrupts
                 assert stream_task.get("error") == history_task.error
                 assert stream_task.get("state") == history_task.state
+
+
+@pytest.mark.parametrize("checkpointer_name", ALL_CHECKPOINTERS_ASYNC)
+async def test_parent_command(checkpointer_name: str) -> None:
+    from langchain_core.messages import BaseMessage
+    from langchain_core.tools import tool
+
+    @tool(return_direct=True)
+    def get_user_name() -> GraphCommand:
+        """Retrieve user name"""
+        return GraphCommand(update={"user_name": "Meow"}, graph=GraphCommand.PARENT)
+
+    subgraph_builder = StateGraph(MessagesState)
+    subgraph_builder.add_node("tool", get_user_name)
+    subgraph_builder.add_edge(START, "tool")
+    subgraph = subgraph_builder.compile()
+
+    class CustomParentState(TypedDict):
+        messages: Annotated[list[BaseMessage], add_messages]
+        # this key is not available to the child graph
+        user_name: str
+
+    builder = StateGraph(CustomParentState)
+    builder.add_node("alice", subgraph)
+    builder.add_edge(START, "alice")
+    async with awith_checkpointer(checkpointer_name) as checkpointer:
+        graph = builder.compile(checkpointer=checkpointer)
+
+        config = {"configurable": {"thread_id": "1"}}
+
+        assert await graph.ainvoke(
+            {"messages": [("user", "get user name")]}, config
+        ) == {
+            "messages": [
+                _AnyIdHumanMessage(
+                    content="get user name", additional_kwargs={}, response_metadata={}
+                ),
+            ],
+            "user_name": "Meow",
+        }
+        assert await graph.aget_state(config) == StateSnapshot(
+            values={
+                "messages": [
+                    _AnyIdHumanMessage(
+                        content="get user name",
+                        additional_kwargs={},
+                        response_metadata={},
+                    ),
+                ],
+                "user_name": "Meow",
+            },
+            next=(),
+            config={
+                "configurable": {
+                    "thread_id": "1",
+                    "checkpoint_ns": "",
+                    "checkpoint_id": AnyStr(),
+                }
+            },
+            metadata={
+                "source": "loop",
+                "writes": {
+                    "alice": {
+                        "user_name": "Meow",
+                    }
+                },
+                "thread_id": "1",
+                "step": 1,
+                "parents": {},
+            },
+            created_at=AnyStr(),
+            parent_config={
+                "configurable": {
+                    "thread_id": "1",
+                    "checkpoint_ns": "",
+                    "checkpoint_id": AnyStr(),
+                }
+            },
+            tasks=(),
+        )