webpack.config.js

const webpack = require("webpack");
const path = require("path");
const ExtractTextWebpackPlugin = require("extract-text-webpack-plugin");
const OptimizeCSSAssets = require("optimize-css-assets-webpack-plugin");
const UglifyJsPlugin = require("uglifyjs-webpack-plugin");



let config = {
    entry: "./src/assets/javascripts/index.js",
    output: {
        path: path.resolve(__dirname, "./public"),
        filename: "./index.js"
    },
    module: {
        rules: [{
                test: /\.js$/,
                exclude: /node_modules/,
                loader: "babel-loader"
            }, {
                test: /\.(scss)$/,
                use: ExtractTextWebpackPlugin.extract({
                    fallback: 'style-loader',
                    use: [{
                        loader: 'css-loader', // translates CSS into CommonJS modules
                    }, {
                        loader: 'postcss-loader', // Run post css actions
                        options: {
                            plugins: function () { // post css plugins, can be exported to postcss.config.js
                                return [
                                    require('precss'),
                                    require('autoprefixer')
                                ];
                            }
                        }
                    }, {
                        loader: 'sass-loader' // compiles Sass to CSS
                    }]
                })
            }, {
                test: /\.css$/,
                use: ExtractTextWebpackPlugin.extract({
                    fallback: 'style-loader',
                    use: ['css-loader']
                })
            },
            {
                test: /\.(woff(2)?|ttf|eot|svg)(\?v=\d+\.\d+\.\d+)?$/,
                use: [{
                    loader: 'file-loader',
                    options: {
                        name: '[name].[ext]',
                        outputPath: 'fonts/'
                    }
                }]
            },
            {
                test: /\.ico?$/,
                use: [{
                    loader: 'file-loader',
                    options: {
                        name: '[name].[ext]',
                        outputPath: 'icons/'
                    }
                }]
            },
            {
                test: /\.(png|jpg|gif|jpeg|svg|tif|JPEG|PNG)?$/,
                use: [{
                    loader: 'file-loader',
                    options: {
                        name: '[name].[ext]',
                        outputPath: 'images/'
                    }
                }]
            }, {
                test: /\.xml?$/,
                use: [{
                    loader: 'raw-loader',
                }]
            }
        ]
    },
    plugins: [
        new ExtractTextWebpackPlugin("styles.css")
    ],
    devServer: {
        contentBase: path.resolve(__dirname, "./public"),
        historyApiFallback: true,
        inline: true,
        open: true,
        hot: true
    },
    devtool: "eval-source-map"
}

module.exports = config;

if (process.env.NODE_ENV === 'production') {
    module.exports.plugins.push(
        new OptimizeCSSAssets()
    );
};