From 928dd90a31095d5d8c6acad194c26a8e8c655189 Mon Sep 17 00:00:00 2001
From: Second-Choice <56642983+icyclv@users.noreply.github.com>
Date: Wed, 23 Jul 2025 16:10:19 +0800
Subject: [PATCH] fix: add nil check in deer-go LoggerCallback to prevent panic
 (#89)

---
 flow/agent/deer-go/biz/infra/logger.go | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/flow/agent/deer-go/biz/infra/logger.go b/flow/agent/deer-go/biz/infra/logger.go
index 0d3a766..0311a7a 100644
--- a/flow/agent/deer-go/biz/infra/logger.go
+++ b/flow/agent/deer-go/biz/infra/logger.go
@@ -125,9 +125,11 @@ func (cb *LoggerCallback) pushMsg(ctx context.Context, msgID string, msg *schema
 
 func (cb *LoggerCallback) OnStart(ctx context.Context, info *callbacks.RunInfo, input callbacks.CallbackInput) context.Context {
 	if inputStr, ok := input.(string); ok {
-		cb.Out <- "\n==================\n"
-		cb.Out <- fmt.Sprintf(" [OnStart] %s ", inputStr)
-		cb.Out <- "\n==================\n"
+		if cb.Out != nil {
+			cb.Out <- "\n==================\n"
+			cb.Out <- fmt.Sprintf(" [OnStart] %s ", inputStr)
+			cb.Out <- "\n==================\n"
+		}
 	}
 	return ctx
 }