PurgeCSS

webpack.base.js

  /**
 * COMMON WEBPACK CONFIGURATION
 */

const path = require('path');
const webpack = require('webpack');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const dotEnv = require('dotenv-webpack');

process.noDeprecation = true;

module.exports = (options) => ({
  mode: options.mode,
  entry: options.entry,
  output: Object.assign({ // Compile into js/build.js
    path: path.resolve(process.cwd(), 'build'),
    publicPath: '/',
  }, options.output), // Merge with env dependent settings
  module: {
    rules: [
      {
        test: /\.js$/, // Transform all .js files required somewhere with Babel
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
          options: options.babelQuery,
        },
      },
      {
        test: /\.(graphql|gql)$/,
        exclude: /node_modules/,
        loader: 'graphql-tag/loader'
      },
      {
        // Preprocess our own .css files
        test: /\.css$/,
        exclude: /node_modules/,
        use: [
          MiniCssExtractPlugin.loader,
          { loader: 'css-loader', options: { importLoaders: 1 } },
          'postcss-loader'
        ],
      },
      {
        // Preprocess 3rd party .css files located in node_modules
        test: /\.css$/,
        include: /node_modules/,
        use: ['style-loader', 'css-loader'],
      },
      {
        test: /\.(eot|svg|otf|ttf|woff|woff2)$/,
        use: 'file-loader',
      },
      {
        test: /\.(jpg|png|gif)$/,
        use: [
          'file-loader',
          {
            loader: 'image-webpack-loader',
            options: {
              query: {
                gifsicle: {
                  interlaced: true
                },
                mozjpeg: {
                  progressive: true
                },
                optipng: {
                  optimizationLevel: 7
                },
                pngquant: {
                  quality: '65-90',
                  speed: 4
                }
              }
            },
          },
        ],
      },
      {
        test: /\.html$/,
        use: 'html-loader'
      },
      {
        test: /\.(mp4|webm)$/,
        use: {
          loader: 'url-loader',
          options: {
            limit: 10000
          },
        },
      },
    ],
  },
  plugins: options.plugins.concat([
    new webpack.ProvidePlugin({
      // make fetch available
      fetch: 'exports-loader?self.fetch!whatwg-fetch'
    }),

    // Always expose NODE_ENV to webpack, in order to use `process.env.NODE_ENV`
    // inside your code for any environment checks; UglifyJS will automatically
    // drop any unreachable code.
    new webpack.DefinePlugin({
      'process.env': {
        NODE_ENV: JSON.stringify(process.env.NODE_ENV)
      },
    }),

    new dotEnv(),

    new MiniCssExtractPlugin({
      filename: '[name].css',
    }),
  ]),
  resolve: {
    modules: ['app', 'node_modules'],
    extensions: [
      '.js',
      '.jsx',
      '.scss',
      '.react.js'
    ],
    mainFields: [
      'browser',
      'jsnext:main',
      'main'
    ]
  },
  devtool: options.devtool,
  target: 'web', // Make web variables accessible to webpack, e.g. window
  performance: options.performance || {},
  optimization: {
    namedModules: true,
    splitChunks: {
      name: 'vendor',
      minChunks: 2,
      cacheGroups: {
        styles: {
          name: 'styles',
          test: /\.css$/,
          chunks: 'all',
          enforce: true
        },
      },
    },
  }
});

webpack.prod.js

/* eslint-disable */
// Important modules this config uses
const path = require('path');
const glob = require('glob-all');
// const webpack = require('webpack');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const PurgecssPlugin = require('purgecss-webpack-plugin');

module.exports = require('./webpack.base.babel')({
  mode: 'production',
  // In production, we skip all hot-reloading stuff
  entry: [
    path.join(process.cwd(), 'app/app.js')
  ],

  // Utilize long-term caching by adding content hashes (not compilation hashes) to compiled assets
  output: {
    filename: '[name].[chunkhash].js',
    chunkFilename: '[name].[chunkhash].chunk.js'
  },

  plugins: [
    new PurgecssPlugin({
      paths: glob.sync([
        path.join(process.cwd(), 'app/**/*.html'),
        path.join(process.cwd(), 'app/**/*.js'),
      ]),
      extractors: [
        {
          extractor: TailwindExtractor,
          extensions: ['html', 'js'],
        }
      ]
    }),

    // Minify and optimize the index.html
    new HtmlWebpackPlugin({
      template: 'app/index.html',
      minify: {
        removeComments: true,
        collapseWhitespace: true,
        removeRedundantAttributes: true,
        useShortDoctype: true,
        removeEmptyAttributes: true,
        removeStyleLinkTypeAttributes: true,
        keepClosingSlash: true,
        minifyJS: true,
        minifyCSS: true,
        minifyURLs: true,
      },
      inject: true
    }),
  ],

  performance: {
    assetFilter: (assetFilename) => !(/(\.map$)|(^(main\.|favicon\.))/.test(assetFilename)),
  },
});

class TailwindExtractor {
  static extract(content) {
    return content.match(/[A-z0-9-:\/]+/g);
  }
}