1、添加sourceMap
sourceMap: true

2、npm run dev 会生成vue.js.map
3、断点调试
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>vue源码测试</title>
</head>
<body>
<div id="app">
<div v-for="item in list"> {{ item }} </div>
</div>
<script src="./vue.js"></script>
<script type="text/javascript">
var app = new Vue({ el: '#app', data: { list: [1, 2, 3] } }) </script>
</body>
</html>