update

node_modules/vue-router/src/util/warn.js

@@ -7,15 +7,8 @@ export function assert (condition: any, message: string) {
 }
 
 export function warn (condition: any, message: string) {
-  if (process.env.NODE_ENV !== 'production' && !condition) {
+  if (!condition) {
     typeof console !== 'undefined' && console.warn(`[vue-router] ${message}`)
   }
 }
 
-export function isError (err: any): boolean {
-  return Object.prototype.toString.call(err).indexOf('Error') > -1
-}
-
-export function isRouterError (err: any, errorType: ?string): boolean {
-  return isError(err) && err._isRouter && (errorType == null || err.type === errorType)
-}