promise reject the brandcheck

Author: Uzlopak

lib/web/fetch/body.js

@@ -438,7 +438,11 @@ function mixinBody (prototype, getInternalState) {
  * @param {(target: any) => any} getInternalState
  */
 function consumeBody (object, convertBytesToJSValue, instance, getInternalState) {
-  webidl.brandCheck(object, instance)
+  try {
+    webidl.brandCheck(object, instance)
+  } catch (e) {
+    return Promise.reject(e)
+  }
 
   const state = getInternalState(object)