feat(transport/http): support redirect errors in default error encoder

Author: tonybase

transport/http/codec.go

@@ -105,6 +105,11 @@ func DefaultResponseEncoder(w http.ResponseWriter, r *http.Request, v any) error
 
 // DefaultErrorEncoder encodes the error to the HTTP response.
 func DefaultErrorEncoder(w http.ResponseWriter, r *http.Request, err error) {
+	if rd, ok := err.(Redirector); ok {
+		url, code := rd.Redirect()
+		http.Redirect(w, r, url, code)
+		return
+	}
 	se := errors.FromError(err)
 	codec, _ := CodecForRequest(r, "Accept")
 	body, err := codec.Marshal(se)

transport/http/redirect.go

@@ -1,5 +1,10 @@
 package http
 
+var (
+	_ error      = (*redirect)(nil)
+	_ Redirector = (*redirect)(nil)
+)
+
 type redirect struct {
 	URL  string
 	Code int
@@ -9,6 +14,10 @@ func (r *redirect) Redirect() (string, int) {
 	return r.URL, r.Code
 }
 
+func (r *redirect) Error() string {
+	return "redirect to " + r.URL
+}
+
 // NewRedirect new a redirect with url, which may be a path relative to the request path.
 // The provided code should be in the 3xx range and is usually StatusMovedPermanently, StatusFound or StatusSeeOther.
 // If the Content-Type header has not been set, Redirect sets it to "text/html; charset=utf-8" and writes a small HTML body.