webpack.config.js

const path = require('path');
const ExtractTextPlugin = require('extract-text-webpack-plugin');

const extractSass = ExtractTextPlugin({
    filename: "[name].[contenthash].css",
    disable: process.env.NODE_ENV === "development"
});

module.exports = {
    entry: '/assets/main.js',
    output: {
        filename: 'bundle.js',
        path: path.resolve(__dirname, 'public')
    },
    module: {
        rules: [{
                test: /\.(png|svg|jpg|gif)$/,
                use: [
                    'file-loader'
                ]
            },
            {
                test: /\.(woff|woff2|eot|ttf|otf)$/,
                use: [
                    'file-loader'
                ]
            },
            {
                test: /\.js$/,
                exclude: /(node_modules|bower_components)/,
                use: [{
                        loader: 'babel-loader',
                        options: {
                            presets: ['env']
                        }
                    },
                    {
                        loader: "jshint-loader"
                    }
                ]
            },
            {
                test: /\.scss$/,
                use: [{
                    loader: "style-loader" // creates style nodes from JS strings
                }, {
                    loader: "css-loader" // translates CSS into CommonJS
                }, {
                    loader: "postcss-loader" // autoprefixer css
                }, {
                    loader: "sass-loader" // compiles Sass to CSS
                }]
            },
            {
                test: /\.css$/,
                use: [{
                    loader: "style-loader" // creates style nodes from JS strings
                }, {
                    loader: "css-loader" // translates CSS into CommonJS
                }, {
                    loader: "postcss-loader" // autoprefixer css
                }]
            }
        ]
    },
    plugins: [
        extractSass
    ]

};