From a91fb5be1d57e5b6dfacf06fde5b8a4bbdc0fadd Mon Sep 17 00:00:00 2001
From: Shunsuke Suzuki <suzuki-shunsuke@users.noreply.github.com>
Date: Thu, 5 Dec 2024 19:09:37 +0900
Subject: [PATCH] Fix a bug ast.Merge removes comments from SequenceNode (#570)

* fix: fix a bug that merge of sequences loses comments

* fix: append null if ValueHeadComments is empty
---
 ast/ast.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/ast/ast.go b/ast/ast.go
index 52edfdf..9c5844a 100644
--- a/ast/ast.go
+++ b/ast/ast.go
@@ -1475,6 +1475,11 @@ func (n *SequenceNode) Merge(target *SequenceNode) {
 	column := n.Start.Position.Column - target.Start.Position.Column
 	target.AddColumn(column)
 	n.Values = append(n.Values, target.Values...)
+	if len(target.ValueHeadComments) == 0 {
+		n.ValueHeadComments = append(n.ValueHeadComments, make([]*CommentGroupNode, len(target.Values))...)
+		return
+	}
+	n.ValueHeadComments = append(n.ValueHeadComments, target.ValueHeadComments...)
 }
 
 // SetIsFlowStyle set value to IsFlowStyle field recursively.