webpack.config.js

var webpack = require('webpack')
var path    = require('path')

module.exports = { 	
	entry : "./src/app.js",		
	output :  
	{
		path  	   : path.resolve(__dirname,'./dist/js'),
		filename   : 'bundle.js'
	},
	module: 
	{ 
		rules:[ 
		{   
			test: /\.css$/, 
			use : ['style-loader', 'css-loader']
		},
		{
			test: /\.js$/,
			exclude: /node_modules/, 
			loader: "babel-loader"
		},
		]
	},
	plugins :[ new webpack.optimize.UglifyJsPlugin]
};

if(process.env.NODE_ENV === 'production'){
	module.exports.plugins.push(new webpack.optimize.UglifyJsPlugin())
}