webpack-dev-server first try

1.

 2. npm install --save-dev --save-exact webpack-dev-server@2.9.1 webpack@3.6.0

 3.

 webpack.config.js

module.exports = {
    entry: './entry.js'
};

//entry.js empty temporary

package.json中加入： "start:dev": "webpack-dev-server"

4.