chore: refine rest validator (#2928)

* chore: refine rest validator

* chore: add more tests

* chore: reformat code

* chore: add comments

rest/httpx/requests.go

@@ -4,6 +4,7 @@ import (
 	"io"
 	"net/http"
 	"strings"
+	"sync/atomic"
 
 	"github.com/zeromicro/go-zero/core/mapping"
 	"github.com/zeromicro/go-zero/rest/internal/encoding"
@@ -23,15 +24,13 @@ const (
 var (
 	formUnmarshaler = mapping.NewUnmarshaler(formKey, mapping.WithStringValues())
 	pathUnmarshaler = mapping.NewUnmarshaler(pathKey, mapping.WithStringValues())
-	xValidator      Validator
+	validator       atomic.Value
 )
 
+// Validator defines the interface for validating the request.
 type Validator interface {
-	Validate(data interface{}, lang string) error
-}
-
-func SetValidator(validator Validator) {
-	xValidator = validator
+	// Validate validates the request and parsed data.
+	Validate(r *http.Request, data any) error
 }
 
 // Parse parses the request.
@@ -52,9 +51,10 @@ func Parse(r *http.Request, v interface{}) error {
 		return err
 	}
 
-	if xValidator != nil {
-		return xValidator.Validate(v, r.Header.Get("Accept-Language"))
+	if val := validator.Load(); val != nil {
+		return val.(Validator).Validate(r, v)
 	}
+
 	return nil
 }
 
@@ -117,6 +117,13 @@ func ParsePath(r *http.Request, v interface{}) error {
 	return pathUnmarshaler.Unmarshal(m, v)
 }
 
+// SetValidator sets the validator.
+// The validator is used to validate the request, only called in Parse,
+// not in ParseHeaders, ParseForm, ParseHeader, ParseJsonBody, ParsePath.
+func SetValidator(val Validator) {
+	validator.Store(val)
+}
+
 func withJsonBody(r *http.Request) bool {
 	return r.ContentLength > 0 && strings.Contains(r.Header.Get(header.ContentType), header.ApplicationJson)
 }