LilSchool/web/webpack.config.js

const webpack = require('webpack');
const path = require('path');
const NODE_ENV = process.env.NODE_ENV || 'development';

module.exports = {
    entry: {
        app: "./src/js/app.js"
    },
    output: {
        path: path.join(__dirname, "build/js"),
        filename: NODE_ENV === 'development' ? '[name].js' : '[name].[id].[chunkhash].js',
        library: '[name]'
    },
    module: {
        loaders: [
            {
                test: /\.js$/,
                exclude: /(node_modules|bower_components)/,
                use: {
                    loader: 'babel-loader',
                    options: {
                        presets: [
                            ["env", {
                              "targets": {
                                "browsers": ["last 2 versions", "safari >= 7"]
                              }
                            }]
                        ]
                    }
                }
            }
        ]
    },
    plugins: [
        new webpack.DefinePlugin({
            'process.env': {
                'NODE_ENV': JSON.stringify(NODE_ENV)
            }
        })
    ],


    watch: NODE_ENV === 'development',

    devtool: NODE_ENV === 'development' ? 'source-map' : false
};

if (NODE_ENV === 'production') {
    module.exports.plugins.push(
        new webpack.optimize.UglifyJsPlugin({
            compress: {
                warnings: false,
                drop_console: true,
                unsafe: true
            }
        })
    );
}