webpack.common.js

const path = require('path');
const webpack = require('webpack');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const ImageMinimizerPlugin = require('image-minimizer-webpack-plugin');

const dirNode = 'node_modules';
const dirApp = path.join(__dirname, 'app');
const dirStyles = path.join(__dirname, 'styles');
const dirAssets = path.join(__dirname, 'assets');

/**
 * Webpack Configuration
 */
module.exports = (env) => {
  // Is the current build a development build
  const IS_DEV = !!env.dev;

  return {
    entry: {
      main: path.join(dirApp, 'index'),
    },

    resolve: {
      modules: [dirNode, dirApp, dirStyles, dirAssets],
    },

    plugins: [
      new webpack.DefinePlugin({ IS_DEV }),

      new HtmlWebpackPlugin({
        template: path.join(__dirname, 'index.ejs'),
        title: 'Webpack Boilerplate',
      }),

      new ImageMinimizerPlugin({
        minimizerOptions: {
          plugins: [
            // SVGO options: "https://github.com/svg/svgo#what-it-can-do"
            [
              'imagemin-svgo',
              {
                plugins: [
                  {
                    removeViewBox: false,
                    removeXMLNS: true,
                  },
                ],
              },
            ],
          ],
        },
      }),
    ],

    module: {
      rules: [
        // BABEL
        {
          test: /\.m?js$/,
          exclude: /(node_modules)/,
          use: {
            loader: 'babel-loader',
            options: {
              compact: true,
            },
          },
        },

        // STYLES
        {
          test: /\.css$/,
          use: [
            'style-loader',
            {
              loader: 'css-loader',
              options: {
                sourceMap: IS_DEV,
              },
            },
          ],
        },

        // CSS / SASS
        {
          test: /\.scss/,
          use: [
            'style-loader',
            {
              loader: 'css-loader',
              options: {
                sourceMap: IS_DEV,
              },
            },
            {
              loader: 'sass-loader',
              options: {
                sourceMap: IS_DEV,
                sassOptions: {
                  includePaths: [dirAssets],
                },
              },
            },
          ],
        },

        // IMAGES
        {
          test: /\.(png|jpe?g|gif)$/i,
          use: {
            loader: 'file-loader',
            options: {
              name: '[path][name].[ext]',
            },
          },
        },

        // SVG
        {
          test: /\.svg$/,
          use: ['raw-loader'],
        },
      ],
    },

    optimization: {
      runtimeChunk: 'single',
    },
  };
};