From d0484ba41212f259b40a01e9fc9abafc75695c5b Mon Sep 17 00:00:00 2001
From: Gabriel Luiz Freitas Almeida <gabriel@langflow.org>
Date: Fri, 9 Aug 2024 11:15:35 -0300
Subject: [PATCH] fix: enhance error handling in build_flow and add error
 handling for Flow build (#3259)

* feat: add error handling for Flow build

The code changes in `buildUtils.ts` add error handling for the Flow build process. It includes a new case for handling errors in the switch statement, which displays the error message and triggers the `onBuildError` function. This change ensures that errors during the Flow build are properly handled and the build process is stopped.

* feat: enhance error handling in build_flow to capture and report HTTP exceptions in the flow building process
---
 src/backend/base/langflow/api/v1/chat.py | 15 ++++++++++++++-
 src/frontend/src/utils/buildUtils.ts     |  8 ++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/backend/base/langflow/api/v1/chat.py b/src/backend/base/langflow/api/v1/chat.py
index 143937d1d..49bf23410 100644
--- a/src/backend/base/langflow/api/v1/chat.py
+++ b/src/backend/base/langflow/api/v1/chat.py
@@ -356,10 +356,23 @@ async def build_flow(
             except asyncio.CancelledError:
                 vertices_task.cancel()
                 return
+            except Exception as e:
+                if isinstance(e, HTTPException):
+                    send_event("error", {"error": str(e.detail), "statusCode": e.status_code}, queue)
+                    raise e
+                send_event("error", {"error": str(e)}, queue)
+                raise e
 
             ids, vertices_to_run, graph = vertices_task.result()
         else:
-            ids, vertices_to_run, graph = await build_graph_and_get_order()
+            try:
+                ids, vertices_to_run, graph = await build_graph_and_get_order()
+            except Exception as e:
+                if isinstance(e, HTTPException):
+                    send_event("error", {"error": str(e.detail), "statusCode": e.status_code}, queue)
+                    raise e
+                send_event("error", {"error": str(e)}, queue)
+                raise e
         send_event("vertices_sorted", {"ids": ids, "to_run": vertices_to_run}, queue)
         await client_consumed_queue.get()
 
diff --git a/src/frontend/src/utils/buildUtils.ts b/src/frontend/src/utils/buildUtils.ts
index 969138598..77dbb8054 100644
--- a/src/frontend/src/utils/buildUtils.ts
+++ b/src/frontend/src/utils/buildUtils.ts
@@ -264,6 +264,14 @@ export async function buildFlowVertices({
         useFlowStore.getState().setIsBuilding(false);
         return true;
       }
+      case "error": {
+        const errorMessage = data.error;
+        console.log(data);
+        onBuildError!("Error Running Flow", [errorMessage], []);
+        buildResults.push(false);
+        useFlowStore.getState().setIsBuilding(false);
+        return true;
+      }
       default:
         return true;
     }