fix(util/gvalid): retrive empty slice parameter in custom validation rule function failed

util/gvalid/gvalid_validator_check_struct.go

@@ -296,12 +296,14 @@ func (v *Validator) doCheckStruct(ctx context.Context, object interface{}) Error
 		if value != nil {
 			switch checkRuleItem.FieldKind {
 			case reflect.Struct, reflect.Map:
+				// empty struct or map.
 				if gconv.String(value) == emptyJsonObjectStr {
-					value = ""
+					value = nil
 				}
 			case reflect.Slice, reflect.Array:
+				// empty slice.
 				if gconv.String(value) == emptyJsonArrayStr {
-					value = ""
+					value = []any{}
 				}
 			default:
 			}

util/gvalid/gvalid_z_unit_issue_test.go

@@ -8,8 +8,15 @@ package gvalid_test
 
 import (
 	"context"
+	"fmt"
 	"testing"
+	"time"
 
+	"github.com/gogf/gf/v2/errors/gerror"
+	"github.com/gogf/gf/v2/frame/g"
+	"github.com/gogf/gf/v2/net/ghttp"
+	"github.com/gogf/gf/v2/test/gtest"
+	"github.com/gogf/gf/v2/util/guid"
 	"github.com/gogf/gf/v2/util/gvalid"
 )
 
@@ -34,3 +41,76 @@ func Test_Issue2503(t *testing.T) {
 		t.Fatal(err)
 	}
 }
+
+type Issue3636SliceV struct{}
+
+func init() {
+	rule := Issue3636SliceV{}
+	gvalid.RegisterRule(rule.Name(), rule.Run)
+}
+
+func (r Issue3636SliceV) Name() string {
+	return "slice-v"
+}
+
+func (r Issue3636SliceV) Message() string {
+	return "not a slice"
+}
+
+func (r Issue3636SliceV) Run(_ context.Context, in gvalid.RuleFuncInput) error {
+	for _, v := range in.Value.Slice() {
+		if v == "" {
+			return gerror.New("empty value")
+		}
+	}
+	if !in.Value.IsSlice() {
+		return gerror.New("not a slice")
+	}
+	return nil
+}
+
+type Issue3636HelloReq struct {
+	g.Meta `path:"/hello" method:"POST"`
+
+	Name string   `json:"name" v:"required" dc:"Your name"`
+	S    []string `json:"s" v:"slice-v" dc:"S"`
+}
+type Issue3636HelloRes struct {
+	Name string   `json:"name" v:"required" dc:"Your name"`
+	S    []string `json:"s" v:"slice-v" dc:"S"`
+}
+
+type Issue3636Hello struct{}
+
+func (Issue3636Hello) Say(ctx context.Context, req *Issue3636HelloReq) (res *Issue3636HelloRes, err error) {
+	res = &Issue3636HelloRes{
+		Name: req.Name,
+		S:    req.S,
+	}
+	return
+}
+
+// https://github.com/gogf/gf/issues/3636
+func Test_Issue3636(t *testing.T) {
+	s := g.Server(guid.S())
+	s.Use(ghttp.MiddlewareHandlerResponse)
+	s.Group("/", func(group *ghttp.RouterGroup) {
+		group.Bind(
+			new(Issue3636Hello),
+		)
+	})
+	s.SetDumpRouterMap(false)
+	s.Start()
+	defer s.Shutdown()
+
+	time.Sleep(100 * time.Millisecond)
+
+	gtest.C(t, func(t *gtest.T) {
+		c := g.Client()
+		c.SetPrefix(fmt.Sprintf("http://127.0.0.1:%d", s.GetListenedPort()))
+		t.Assert(
+			c.PostContent(ctx, "/hello", `{"name": "t", "s" : []}`),
+			`{"code":0,"message":"","data":{"name":"t","s":[]}}`,
+		)
+	})
+}