webpack.config.js

const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const devMode = process.env.NODE_ENV !== 'production'

module.exports = {
    entry: './src/main/resources/assets/js/index.js',
    output: {
        filename: './js/index.js',
        path: __dirname + '/src/main/resources/static/'
    },
    module: {
        rules: [
            {
                test: /\.js$/,
                exclude: /node_modules/,
                use: {
                    loader: "babel-loader"
                }
            },
            {
                test: /\.scss$/,
                use: [
                    {
                        loader: MiniCssExtractPlugin.loader
                    },
                    {
                        loader: "css-loader", options: {
                            sourceMap: true
                        }
                    },
                    {
                        loader: 'postcss-loader',
                        options: {
                            plugins: function () {
                                return [
                                    require('precss'),
                                    require('autoprefixer')
                                ];
                            }
                        }
                    },
                    {
                        loader: "sass-loader", options: {
                            sourceMap: true
                        }
                    }
                ]
            }
        ]
    },
    plugins: [
        new MiniCssExtractPlugin({
            filename:  '/css/[name].css'
        })
    ]
};