From b9268df91b16ddbebc65f09f642d7a0d3335526c Mon Sep 17 00:00:00 2001
From: Clark Du <clark.duxin@gmail.com>
Date: Thu, 30 Nov 2017 14:03:25 +0800
Subject: [PATCH] fix(dev-watching): mixins not removed after function changed
 or deleted

---
 lib/builder/builder.js | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/builder/builder.js b/lib/builder/builder.js
index 1325cc2ca8..45c57269c0 100644
--- a/lib/builder/builder.js
+++ b/lib/builder/builder.js
@@ -459,6 +459,9 @@ export default class Builder {
           compiler.watch(this.options.watchers.webpack, (err) => {
             /* istanbul ignore if */
             if (err) return reject(err)
+            // not keep modified or deleted items in Vue.prototype
+            delete require.cache[require.resolve('vue')]
+            delete require.cache[require.resolve('vue-router')]
           })
         )
         return