simplify code with http.Flusher type conversion (#325)

* simplify code with http.Flusher type conversion

* simplify code with http.Flusher type conversion, better version

rest/handler/authhandler.go

@@ -46,18 +46,18 @@ func Authorize(secret string, opts ...AuthorizeOption) func(http.Handler) http.H
 	parser := token.NewTokenParser()
 	return func(next http.Handler) http.Handler {
 		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			token, err := parser.ParseToken(r, secret, authOpts.PrevSecret)
+			tok, err := parser.ParseToken(r, secret, authOpts.PrevSecret)
 			if err != nil {
 				unauthorized(w, r, err, authOpts.Callback)
 				return
 			}
 
-			if !token.Valid {
+			if !tok.Valid {
 				unauthorized(w, r, errInvalidToken, authOpts.Callback)
 				return
 			}
 
-			claims, ok := token.Claims.(jwt.MapClaims)
+			claims, ok := tok.Claims.(jwt.MapClaims)
 			if !ok {
 				unauthorized(w, r, errNoClaims, authOpts.Callback)
 				return
@@ -122,6 +122,12 @@ func newGuardedResponseWriter(w http.ResponseWriter) *guardedResponseWriter {
 	}
 }
 
+func (grw *guardedResponseWriter) Flush() {
+	if flusher, ok := grw.writer.(http.Flusher); ok {
+		flusher.Flush()
+	}
+}
+
 func (grw *guardedResponseWriter) Header() http.Header {
 	return grw.writer.Header()
 }
@@ -138,9 +144,3 @@ func (grw *guardedResponseWriter) WriteHeader(statusCode int) {
 	grw.wroteHeader = true
 	grw.writer.WriteHeader(statusCode)
 }
-
-func (grw *guardedResponseWriter) Flush() {
-	if flusher, ok := grw.writer.(http.Flusher); ok {
-		flusher.Flush()
-	}
-}