From 0d31e6c3752b63e8bcaba896e96cacdefec0c5ec Mon Sep 17 00:00:00 2001
From: kesonan <anqiansong@gmail.com>
Date: Sat, 14 Jun 2025 23:36:30 +0800
Subject: [PATCH] (goctl): fix #4943 (#4953)

---
 tools/goctl/api/spec/tags.go      |  9 ++++
 tools/goctl/api/spec/tags_test.go | 68 +++++++++++++++++++++++++++++++
 2 files changed, 77 insertions(+)
 create mode 100644 tools/goctl/api/spec/tags_test.go

diff --git a/tools/goctl/api/spec/tags.go b/tools/goctl/api/spec/tags.go
index 312772d35..1e3d153b3 100644
--- a/tools/goctl/api/spec/tags.go
+++ b/tools/goctl/api/spec/tags.go
@@ -49,6 +49,9 @@ func Parse(tag string) (*Tags, error) {
 
 // Get gets tag value by specified key
 func (t *Tags) Get(key string) (*Tag, error) {
+	if t == nil {
+		return nil, errTagNotExist
+	}
 	for _, tag := range t.tags {
 		if tag.Key == key {
 			return tag, nil
@@ -60,6 +63,9 @@ func (t *Tags) Get(key string) (*Tag, error) {
 
 // Keys returns all keys in Tags
 func (t *Tags) Keys() []string {
+	if t == nil {
+		return []string{}
+	}
 	var keys []string
 	for _, tag := range t.tags {
 		keys = append(keys, tag.Key)
@@ -69,5 +75,8 @@ func (t *Tags) Keys() []string {
 
 // Tags returns all tags in Tags
 func (t *Tags) Tags() []*Tag {
+	if t == nil {
+		return []*Tag{}
+	}
 	return t.tags
 }
diff --git a/tools/goctl/api/spec/tags_test.go b/tools/goctl/api/spec/tags_test.go
new file mode 100644
index 000000000..417b1f621
--- /dev/null
+++ b/tools/goctl/api/spec/tags_test.go
@@ -0,0 +1,68 @@
+package spec
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestTags_Get(t *testing.T) {
+	tags := &Tags{
+		tags: []*Tag{
+			{Key: "json", Name: "foo", Options: []string{"omitempty"}},
+			{Key: "xml", Name: "bar", Options: nil},
+		},
+	}
+
+	tag, err := tags.Get("json")
+	assert.NoError(t, err)
+	assert.NotNil(t, tag)
+	assert.Equal(t, "json", tag.Key)
+	assert.Equal(t, "foo", tag.Name)
+
+	_, err = tags.Get("yaml")
+	assert.Error(t, err)
+
+	var nilTags *Tags
+	_, err = nilTags.Get("json")
+	assert.Error(t, err)
+}
+
+func TestTags_Keys(t *testing.T) {
+	tags := &Tags{
+		tags: []*Tag{
+			{Key: "json", Name: "foo", Options: []string{"omitempty"}},
+			{Key: "xml", Name: "bar", Options: nil},
+		},
+	}
+
+	keys := tags.Keys()
+	expected := []string{"json", "xml"}
+	assert.Equal(t, expected, keys)
+
+	var nilTags *Tags
+	nilKeys := nilTags.Keys()
+	assert.Empty(t, nilKeys)
+}
+
+func TestTags_Tags(t *testing.T) {
+	tags := &Tags{
+		tags: []*Tag{
+			{Key: "json", Name: "foo", Options: []string{"omitempty"}},
+			{Key: "xml", Name: "bar", Options: nil},
+		},
+	}
+
+	result := tags.Tags()
+	assert.Len(t, result, 2)
+	assert.Equal(t, "json", result[0].Key)
+	assert.Equal(t, "foo", result[0].Name)
+	assert.Equal(t, []string{"omitempty"}, result[0].Options)
+	assert.Equal(t, "xml", result[1].Key)
+	assert.Equal(t, "bar", result[1].Name)
+	assert.Nil(t, result[1].Options)
+
+	var nilTags *Tags
+	nilResult := nilTags.Tags()
+	assert.Empty(t, nilResult)
+}