webpack.config.js

const webpack = require("webpack");
const OptimizeCssAssetsPlugin = require("optimize-css-assets-webpack-plugin");
const HtmlWebpackPlugin = require("html-webpack-plugin");
const version = require("./package.json").version;
const path = require("path");

module.exports = (env = {}) => {
  // set env as empty object if unset from cli
  let mode;
  if (env.production || env.devbuild) {
    mode = "production";
  } else {
    mode = "development";
  }

  let config = {
    mode: mode,
    entry: {
      app: "./src/app.js"
    },
    output: {
      path: path.resolve(__dirname, "dist"),
      filename: "[name].bundle.js"
    },
    module: {
      rules: [
        {
          test: /\.js$/,
          exclude: path.resolve(__dirname, "node_modules"),
          use: {
            loader: "babel-loader",
            options: {
              presets: [
                [
                  "@babel/preset-env",
                  {
                    targets: {
                      browsers: ["ie 11"]
                    }
                  }
                ]
              ]
            }
          }
        },
        {
          test: /\.(png|jpg|gif|eot|otf|svg|ttf|woff|woff2)$/,
          use: [
            {
              loader: "url-loader",
              options: {
                limit: 8192, // byte limit to inline files as data URL
                name: "assets/[name].[ext]" // path to file for file-loader fallback
              }
            }
          ]
        },
        {
          test: /\.css$/,
          use: ["style-loader", "css-loader"]
        },
        {
          test: /\.html$/,
          use: {
            loader: "html-loader",
            options: {
              removeComments: true,
              collapseWhitespace: true
            }
          }
        }
      ]
    },
    plugins: [
      new webpack.DefinePlugin({
        VERSION: JSON.stringify(version)
      }),
      new HtmlWebpackPlugin({
        title: "Apex Signature Validator",
        template: "index.ejs"
      })
    ],
    optimization: {
      splitChunks: {
        chunks: "all"
      }
    },
    devServer: {
      contentBase: path.resolve(__dirname, "dist")
    }
  };

  if (env.production) {
    // PRODUCTION
    config.plugins.push(new OptimizeCssAssetsPlugin()); // minify css
  }
  return config;
};