🐛 fix(flow.py): make flow field optional to allow creation of flows without a flow

🧪 test(test_database.py): add test case for creating flows without a flow
The flow field is now optional to allow creation of flows without a flow. This is useful when creating a flow that will be populated later. A test case was added to ensure that flows can be created without a flow.

src/backend/langflow/database/models/flow.py

@@ -12,11 +12,13 @@ from langflow.database.models.flow_style import FlowStyle, FlowStyleRead
 
 class FlowBase(SQLModelSerializable):
     name: str = Field(index=True)
-    flow: Dict = Field(default_factory=dict, sa_column=Column(JSON))
+    flow: Optional[Dict] = Field(default_factory=dict, sa_column=Column(JSON))
 
     @validator("flow")
     def validate_json(v):
         # dict_keys(['description', 'name', 'id', 'data'])
+        if not v:
+            return v
         if not isinstance(v, dict):
             raise ValueError("Flow must be a valid JSON")
         if "description" not in v.keys():

tests/test_database.py

@@ -38,6 +38,12 @@ def test_create_flow(client: TestClient, json_flow: str):
     assert response.status_code == 200
     assert response.json()["name"] == flow.name
     assert response.json()["flow"] == flow.flow
+    # flow is optional so we can create a flow without a flow
+    flow = FlowCreate(name="Test Flow")
+    response = client.post("api/v1/flows/", json=flow.dict(exclude_unset=True))
+    assert response.status_code == 200
+    assert response.json()["name"] == flow.name
+    assert response.json()["flow"] == flow.flow
 
 
 def test_read_flows(client: TestClient, json_flow: str):