webpack.config.dev.js

const path = require("path");
const webpack = require ("webpack");

module.exports = {
    entry: './index.js',
    output:{
        //设置出口文件
    },
    plugins:[
        new webpack.HotModuleReplacementPlugin()
          //注意是数组
    ],
    devServer: {
        port: 9000,
        contentBase: "./", 
        historyApiFallback: true,
        inline:true,
        hot: true
    }                
}