webpack.config.js

let webpack = require('webpack');
let path = require('path');
const glob = require('glob')
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const PurgecssPlugin = require('purgecss-webpack-plugin')



module.exports = {
    entry: [
        './src/js/main.js',
        './src/scss/main.scss'
    ],

    output: {
        path: path.resolve(__dirname, 'dist'),
        filename: 'main.js',
    },
    module: {
        rules: [
            { 
                test: /\.js$/, 
                exclude: /node_modules/, 
                loader: 'babel-loader'
            },
            {
                test: /\.(png|jpe?g|gif)$/i,
                use: [
                  {
                    loader: 'file-loader',
                    options: {
                        name: '[name].[hash].[ext]',
                        outputPath: 'images',
                    },
                  },
                ],
            },
            {
                test: /\.(woff(2)?|ttf|eot|svg)(\?v=\d+\.\d+\.\d+)?$/,
                use: [
                    {
                        loader: 'file-loader',
                        options: {
                            name: '[name].[hash].[ext]',
                            outputPath: 'fonts'
                        }
                    }
                ]
            },
            {
                test: /\.s[ac]ss$/i,
                use: [
                  MiniCssExtractPlugin.loader,
                  {
                    loader: 'css-loader',
                    options: {
                      sourceMap: true,
                      url: true,
                    },
                  },
                  {
                    loader: 'postcss-loader',
                    options: {
                        sourceMap: true,
                        config: {
                            path: 'postcss.config.js'
                        }
                    }
                  },    
                  {
                    loader: 'sass-loader',
                    options: {
                      sourceMap: true,
                    },
                  },
                ],
            },
        ]
    },

    plugins: [
        new MiniCssExtractPlugin({
            filename: '[name].css',
            chunkFilename: '[id].css',
        })
    ],
}

if(process.env.NODE_ENV === 'production'){
    module.exports.plugins.push(
        new webpack.optimize.UglifyJsPlugin()
    );
    module.exports.plugins.push(
        new webpack.optimize.PurgecssPlugin({ paths: glob.sync(path.join(__dirname, '*.html'),  { nodir: true }) })
    );
}