Add async tests

libs/langgraph/tests/test_pregel_async.py

@@ -9820,6 +9820,71 @@ async def test_store_injected_async(checkpointer_name: str, store_name: str) ->
         )  # still overwriting the same one
 
 
+async def test_debug_retry():
+    class State(TypedDict):
+        messages: Annotated[list[str], operator.add]
+
+    def node(name):
+        async def _node(state: State):
+            return {"messages": [f"entered {name} node"]}
+
+        return _node
+
+    builder = StateGraph(State)
+    builder.add_node("one", node("one"))
+    builder.add_node("two", node("two"))
+    builder.add_edge(START, "one")
+    builder.add_edge("one", "two")
+    builder.add_edge("two", END)
+
+    saver = MemorySaver()
+
+    graph = builder.compile(checkpointer=saver)
+
+    config = {"configurable": {"thread_id": "1"}}
+    await graph.ainvoke({"messages": []}, config=config)
+
+    # re-run step: 1
+    async for c in saver.alist(config):
+        if c.metadata["step"] == 1:
+            target_config = c.parent_config
+            break
+    assert target_config is not None
+
+    update_config = await graph.aupdate_state(target_config, values=None)
+
+    events = [
+        c async for c in graph.astream(None, config=update_config, stream_mode="debug")
+    ]
+
+    checkpoint_events = list(
+        reversed([e["payload"] for e in events if e["type"] == "checkpoint"])
+    )
+
+    checkpoint_history = {
+        c.config["configurable"]["checkpoint_id"]: c
+        async for c in graph.aget_state_history(config)
+    }
+
+    def lax_normalize_config(config: Optional[dict]) -> Optional[dict]:
+        if config is None:
+            return None
+        return config["configurable"]
+
+    for stream in checkpoint_events:
+        stream_conf = lax_normalize_config(stream["config"])
+        stream_parent_conf = lax_normalize_config(stream["parent_config"])
+        assert stream_conf != stream_parent_conf
+
+        # ensure the streamed checkpoint == checkpoint from checkpointer.list()
+        history = checkpoint_history[stream["config"]["configurable"]["checkpoint_id"]]
+        history_conf = lax_normalize_config(history.config)
+        assert stream_conf == history_conf
+
+        history_parent_conf = lax_normalize_config(history.parent_config)
+        assert stream_parent_conf == history_parent_conf
+
+
 async def test_debug_subgraphs():
     class State(TypedDict):
         messages: Annotated[list[str], operator.add]