fix: change ValueError into Warning to allow disconnected flows to run and other small fixes

src/backend/base/langflow/api/v1/chat.py

@@ -370,6 +370,7 @@ async def event_generator(queue: asyncio.Queue, client_consumed_queue: asyncio.Q
         try:
             await asyncio.gather(*tasks)
         except asyncio.CancelledError:
+            background_tasks.add_task(graph.end_all_traces)
             for task in tasks:
                 task.cancel()
             return

src/backend/base/langflow/graph/graph/base.py

@@ -7,6 +7,7 @@
 from functools import partial
 from itertools import chain
 from typing import TYPE_CHECKING, Any, Dict, Generator, List, Optional, Tuple, Type, Union
+import warnings
 
 import nest_asyncio
 from loguru import logger
@@ -1425,7 +1426,7 @@ def _build_edges(self) -> List[ContractEdge]:
             new_edge = self.build_edge(edge)
             edges.add(new_edge)
         if self.vertices and not edges:
-            raise ValueError("Graph has vertices but no edges")
+            warnings.warn("Graph has vertices but no edges")
         return list(edges)
 
     def build_edge(self, edge: EdgeData) -> ContractEdge:

src/backend/tests/unit/graph/graph/test_base.py

@@ -32,7 +32,7 @@ async def test_graph():
     graph = Graph()
     graph.add_component("chat_input", chat_input)
     graph.add_component("chat_output", chat_output)
-    with pytest.raises(ValueError, match="Graph has vertices but no edges"):
+    with pytest.warns(UserWarning, match="Graph has vertices but no edges"):
         graph.prepare()
 
 

src/backend/tests/unit/initial_setup/starter_projects/test_vector_store_rag.py

@@ -212,7 +212,7 @@ def test_vector_store_rag_dump_components_and_edges(ingestion_graph, rag_graph):
         assert (source, target) in expected_rag_edges, f"Edge {source} -> {target} not found"
 
 
-def test_vector_store_rag_add(ingestion_graph, rag_graph):
+def test_vector_store_rag_add(ingestion_graph: Graph, rag_graph: Graph):
     ingestion_graph_copy = copy.deepcopy(ingestion_graph)
     rag_graph_copy = copy.deepcopy(rag_graph)
     ingestion_graph_copy += rag_graph_copy

src/backend/tests/unit/test_database.py

@@ -212,7 +212,7 @@ def test_create_flows(client: TestClient, session: Session, json_flow: str, logg
     # Check response data
     response_data = response.json()
     assert len(response_data) == 2
-    assert response_data[0]["name"] == "Flow 1"
+    assert "Flow 1" in response_data[0]["name"]
     assert response_data[0]["description"] == "description"
     assert response_data[0]["data"] == data
     assert response_data[1]["name"] == "Flow 2"
@@ -241,7 +241,7 @@ def test_upload_file(client: TestClient, session: Session, json_flow: str, logge
     # Check response data
     response_data = response.json()
     assert len(response_data) == 2
-    assert response_data[0]["name"] == "Flow 1"
+    assert "Flow 1" in response_data[0]["name"]
     assert response_data[0]["description"] == "description"
     assert response_data[0]["data"] == data
     assert response_data[1]["name"] == "Flow 2"