fix: Improve update_flow data consistency, refine error handling, and add folder-moving tests (langflow-ai#5516)

* 🐛 (flows.py): Fix issue where flow data was not being properly updated in the database during flow update
📝 (flows.py): Improve error handling and rollback database session in case of exceptions during flow update
📝 (flows.py): Refactor code to handle unique constraint errors and provide more informative error messages
📝 (utils.py): Refactor get_webhook_component_in_flow function to handle cases where flow_data may not have 'nodes' attribute

* ✨ (sideBarFolderButtons/index.tsx): add unique id attribute to sidebar folder buttons for improved accessibility and testing
✨ (general-bugs-move-flow-from-folder.spec.ts): add test to ensure user can move flow from one folder to another in the frontend application

* 🐛 (flows.py): remove unnecessary session rollback to prevent potential data inconsistency
♻️ (service.py): refactor with_session method to handle session commit and rollback more effectively

* style: adjust line breaks for readability

* style: reorder imports

* fix: ruff error try300

* [autofix.ci] apply automated fixes

* fix: mypy error module has no attribute "timeout"

* 🐛 (flows.py): remove unnecessary error handling code and improve exception handling for better error propagation and clarity

* [autofix.ci] apply automated fixes

* Update src/backend/base/langflow/services/database/service.py

Co-authored-by: Gabriel Luiz Freitas Almeida <[email protected]>

* use model dump besides overwrite value

* [autofix.ci] apply automated fixes

* 📝 (chat.py): improve code readability by refactoring session handling and adding comments for clarity
🔧 (chat.py): refactor code to create a fresh session for database operations and improve session management in build_flow function

* [autofix.ci] apply automated fixes

* refactor: remove unused session parameter from build_flow function in chat.py

---------

Co-authored-by: italojohnny <[email protected]>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Gabriel Luiz Freitas Almeida <[email protected]>

Author: 4 people

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

@@ -152,7 +152,6 @@ async def build_flow(
     start_component_id: str | None = None,
     log_builds: bool | None = True,
     current_user: CurrentActiveUser,
-    session: DbSession,
 ):
     chat_service = get_chat_service()
     telemetry_service = get_telemetry_service()
@@ -164,15 +163,20 @@ async def build_graph_and_get_order() -> tuple[list[str], list[str], Graph]:
         components_count = None
         try:
             flow_id_str = str(flow_id)
-            if not data:
-                graph = await build_graph_from_db(flow_id=flow_id, session=session, chat_service=chat_service)
-            else:
-                async with session_scope() as new_session:
-                    result = await new_session.exec(select(Flow.name).where(Flow.id == flow_id))
+            # Create a fresh session for database operations
+            async with session_scope() as fresh_session:
+                if not data:
+                    graph = await build_graph_from_db(flow_id=flow_id, session=fresh_session, chat_service=chat_service)
+                else:
+                    result = await fresh_session.exec(select(Flow.name).where(Flow.id == flow_id))
                     flow_name = result.first()
-                graph = await build_graph_from_data(
-                    flow_id=flow_id_str, payload=data.model_dump(), user_id=str(current_user.id), flow_name=flow_name
-                )
+                    graph = await build_graph_from_data(
+                        flow_id=flow_id_str,
+                        payload=data.model_dump(),
+                        user_id=str(current_user.id),
+                        flow_name=flow_name,
+                    )
+
             graph.validate_stream()
             if stop_component_id or start_component_id:
                 try:

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

@@ -271,18 +271,18 @@ async def update_flow(
             user_id=current_user.id,
             settings_service=settings_service,
         )
-    except Exception as e:
-        raise HTTPException(status_code=500, detail=str(e)) from e
 
-    if not db_flow:
-        raise HTTPException(status_code=404, detail="Flow not found")
+        if not db_flow:
+            raise HTTPException(status_code=404, detail="Flow not found")
+
+        update_data = flow.model_dump(exclude_unset=True, exclude_none=True)
 
-    try:
-        flow_data = flow.model_dump(exclude_unset=True)
         if settings_service.settings.remove_api_keys:
-            flow_data = remove_api_keys(flow_data)
-        for key, value in flow_data.items():
+            update_data = remove_api_keys(update_data)
+
+        for key, value in update_data.items():
             setattr(db_flow, key, value)
+
         webhook_component = get_webhook_component_in_flow(db_flow.data)
         db_flow.webhook = webhook_component is not None
         db_flow.updated_at = datetime.now(timezone.utc)
@@ -291,24 +291,25 @@ async def update_flow(
             default_folder = (await session.exec(select(Folder).where(Folder.name == DEFAULT_FOLDER_NAME))).first()
             if default_folder:
                 db_flow.folder_id = default_folder.id
+
         session.add(db_flow)
         await session.commit()
         await session.refresh(db_flow)
+
     except Exception as e:
-        # If it is a validation error, return the error message
-        if hasattr(e, "errors"):
-            raise HTTPException(status_code=400, detail=str(e)) from e
         if "UNIQUE constraint failed" in str(e):
             # Get the name of the column that failed
             columns = str(e).split("UNIQUE constraint failed: ")[1].split(".")[1].split("\n")[0]
             # UNIQUE constraint failed: flow.user_id, flow.name
             # or UNIQUE constraint failed: flow.name
             # if the column has id in it, we want the other column
             column = columns.split(",")[1] if "id" in columns.split(",")[0] else columns.split(",")[0]
-
             raise HTTPException(
                 status_code=400, detail=f"{column.capitalize().replace('_', ' ')} must be unique"
             ) from e
+
+        if hasattr(e, "status_code"):
+            raise HTTPException(status_code=e.status_code, detail=str(e)) from e
         raise HTTPException(status_code=500, detail=str(e)) from e
 
     return db_flow

src/backend/base/langflow/services/database/models/flow/utils.py

@@ -5,9 +5,10 @@
 
 def get_webhook_component_in_flow(flow_data: dict):
     """Get webhook component in flow data."""
-    for node in flow_data.get("nodes", []):
-        if "Webhook" in node.get("id"):
-            return node
+    if hasattr(flow_data, "nodes"):
+        for node in flow_data.get("nodes", []):
+            if "Webhook" in node.get("id"):
+                return node
     return None
 
 

src/backend/base/langflow/services/database/service.py

@@ -136,7 +136,14 @@ def on_connection(self, dbapi_connection, _connection_record) -> None:
     @asynccontextmanager
     async def with_session(self):
         async with AsyncSession(self.engine, expire_on_commit=False) as session:
-            yield session
+            try:
+                yield session
+                if session.is_active:
+                    await session.commit()
+            except Exception:
+                logger.error("An error occurred during the session scope.")
+                await session.rollback()
+                raise
 
     async def assign_orphaned_flows_to_superuser(self) -> None:
         """Assign orphaned flows to the default superuser when auto login is enabled."""

src/frontend/src/components/core/folderSidebarComponent/components/sideBarFolderButtons/index.tsx

@@ -373,6 +373,7 @@ const SideBarFoldersButtonsComponent = ({
                           onDrop={(e) => onDrop(e, item.id!)}
                           key={item.id}
                           data-testid={`sidebar-nav-${item.name}`}
+                          id={`sidebar-nav-${item.name}`}
                           isActive={checkPathName(item.id!)}
                           onClick={() => handleChangeFolder!(item.id!)}
                           className={cn(

src/frontend/tests/extended/regression/general-bugs-move-flow-from-folder.spec.ts

@@ -0,0 +1,54 @@
+import { expect, test } from "@playwright/test";
+import { awaitBootstrapTest } from "../../utils/await-bootstrap-test";
+
+test("user must be able to move flow from folder", async ({ page }) => {
+  const randomName = Math.random().toString(36).substring(2, 15);
+
+  await awaitBootstrapTest(page);
+
+  await page.getByTestId("side_nav_options_all-templates").click();
+  await page.getByRole("heading", { name: "Basic Prompting" }).click();
+
+  await page.waitForSelector('[data-testid="flow_name"]', {
+    timeout: 3000,
+  });
+
+  await page.getByTestId("flow_name").click();
+  await page.getByText("Flow Settings").first().click();
+  await page.getByPlaceholder("Flow name").fill(randomName);
+
+  await page.getByTestId("save-flow-settings").click();
+
+  await page.getByText("Changes saved successfully").isVisible();
+
+  await page.getByTestId("icon-ChevronLeft").click();
+  await page.waitForSelector('[data-testid="add-folder-button"]', {
+    timeout: 3000,
+  });
+
+  await page.getByTestId("add-folder-button").click();
+
+  //wait for the folder to be created and changed to the new folder
+  await page.waitForTimeout(1000);
+
+  await page.getByTestId("sidebar-nav-My Projects").click();
+
+  await page.getByText(randomName).hover();
+
+  await page
+    .getByTestId("list-card")
+    .first()
+    .dragTo(page.locator('//*[@id="sidebar-nav-New Folder"]'));
+
+  //wait for the drag and drop to be completed
+  await page.waitForTimeout(1000);
+
+  await page.getByTestId("sidebar-nav-New Folder").click();
+
+  await page.waitForSelector('[data-testid="list-card"]', {
+    timeout: 3000,
+  });
+
+  const flowNameCount = await page.getByText(randomName).count();
+  expect(flowNameCount).toBeGreaterThan(0);
+});