fix: empty flow assistant logs when no updates occur

- Added a mechanism to track updates in the flow assistant log worker.
- Implemented a new database function to delete flow assistant logs if no updates are made during processing.
- Updated the querier interface to include the new delete function.
- Enhanced SQL model to support the deletion of flow assistant logs.

backend/pkg/controller/aslog.go

@@ -292,6 +292,7 @@ func (aslw *flowAssistantLogWorker) workerMsgUpdater(
 	contentBuf := bytes.NewBuffer(contentData)
 	thinkingData := make([]byte, 0, defaultMaxMessageLength)
 	thinkingBuf := bytes.NewBuffer(thinkingData)
+	wasUpdated := false // track if we actually updated the record
 
 	msgLog, err := aslw.db.GetFlowAssistantLog(ctx, msgID)
 	if err != nil {
@@ -336,15 +337,18 @@ func (aslw *flowAssistantLogWorker) workerMsgUpdater(
 				ID:       msgID,
 			})
 			if err == nil {
+				wasUpdated = true
 				aslw.pub.AssistantLogUpdated(ctx, msgLog, false)
 			}
 
 		case providers.StreamMessageChunkTypeContent:
 			contentBuf.WriteString(chunk.Content)
+			wasUpdated = true
 			aslw.pub.AssistantLogUpdated(ctx, newLog(chunk.MsgType, chunk.Content, ""), true)
 
 		case providers.StreamMessageChunkTypeThinking:
 			thinkingBuf.WriteString(aslw.getThinkingString(chunk.Thinking))
+			wasUpdated = true
 			aslw.pub.AssistantLogUpdated(ctx, newLog(chunk.MsgType, "", aslw.getThinkingString(chunk.Thinking)), true)
 
 		case providers.StreamMessageChunkTypeResult:
@@ -360,6 +364,7 @@ func (aslw *flowAssistantLogWorker) workerMsgUpdater(
 				ID:           msgID,
 			})
 			if err == nil {
+				wasUpdated = true
 				aslw.pub.AssistantLogUpdated(ctx, msgLog, false)
 			}
 		}
@@ -375,7 +380,10 @@ func (aslw *flowAssistantLogWorker) workerMsgUpdater(
 				processChunk(<-ch)
 			}
 
-			if msgLog, err = aslw.db.GetFlowAssistantLog(ctx, msgID); err == nil {
+			// If record was never updated, delete it (empty message case)
+			if !wasUpdated {
+				_ = aslw.db.DeleteFlowAssistantLog(ctx, msgID)
+			} else if msgLog, err = aslw.db.GetFlowAssistantLog(ctx, msgID); err == nil {
 				content, thinking := contentBuf.String(), thinkingBuf.String()
 				_, _ = aslw.db.UpdateAssistantLog(ctx, database.UpdateAssistantLogParams{
 					Type:         msgLog.Type,

backend/pkg/database/assistantlogs.sql.go

@@ -106,6 +106,16 @@ func (q *Queries) CreateResultAssistantLog(ctx context.Context, arg CreateResult
 	return i, err
 }
 
+const deleteFlowAssistantLog = `-- name: DeleteFlowAssistantLog :exec
+DELETE FROM assistantlogs
+WHERE id = $1
+`
+
+func (q *Queries) DeleteFlowAssistantLog(ctx context.Context, id int64) error {
+	_, err := q.db.ExecContext(ctx, deleteFlowAssistantLog, id)
+	return err
+}
+
 const getFlowAssistantLog = `-- name: GetFlowAssistantLog :one
 SELECT
   al.id, al.type, al.message, al.result, al.result_format, al.flow_id, al.assistant_id, al.created_at, al.thinking

backend/pkg/database/querier.go

@@ -36,6 +36,7 @@ type Querier interface {
 	DeleteAssistant(ctx context.Context, id int64) (Assistant, error)
 	DeleteFavoriteFlow(ctx context.Context, arg DeleteFavoriteFlowParams) (UserPreference, error)
 	DeleteFlow(ctx context.Context, id int64) (Flow, error)
+	DeleteFlowAssistantLog(ctx context.Context, id int64) error
 	DeletePrompt(ctx context.Context, id int64) error
 	DeleteProvider(ctx context.Context, id int64) (Provider, error)
 	DeleteSubtask(ctx context.Context, id int64) error

backend/pkg/tools/executor.go

@@ -280,7 +280,7 @@ func (ce *customExecutor) Execute(
 
 	var err error
 	msgID, msg := int64(0), ce.getMessage(args)
-	if msg != "" {
+	if strings.Trim(msg, " \t\n\r") != "" {
 		msgType := getMessageType(name)
 		msgID, err = ce.mlp.PutMsg(ctx, msgType, ce.taskID, ce.subtaskID, streamID, thinking, msg)
 		if err != nil {

backend/sqlc/models/assistantlogs.sql

@@ -70,3 +70,7 @@ UPDATE assistantlogs
 SET result = $1, result_format = $2
 WHERE id = $3
 RETURNING *;
+
+-- name: DeleteFlowAssistantLog :exec
+DELETE FROM assistantlogs
+WHERE id = $1;