webpack.config.babel.ts

import { merge } from "webpack-merge";
import path from "path";
import { Configuration } from "webpack";
import HtmlWebpackPlugin from "html-webpack-plugin";
import { CleanWebpackPlugin } from "clean-webpack-plugin";
import { BundleAnalyzerPlugin } from "webpack-bundle-analyzer";
import MiniCssExtractPlugin from "mini-css-extract-plugin";
import CssMinimizerPlugin from "css-minimizer-webpack-plugin";

const commonConfig: Configuration = {
  entry: path.resolve(__dirname, "src", "index.tsx"),
  output: {
    path: path.join(__dirname, "dist"),
    filename: "bundle.js",
  },
  resolve: {
    extensions: [".tsx", ".ts", "jsx", ".js"],
  },
  module: {
    rules: [
      {
        test: /\.(js|jsx|ts|tsx)$/,
        use: "babel-loader",
        exclude: /node_modules/,
      },
    ],
  },
  plugins: [
    new HtmlWebpackPlugin({
      template: "src/index.html",
    }),
  ],
};

const stylesRegex = /\.(sa|sc|c)ss$/;
const commonStyleLoaders = [
  { loader: "css-loader", options: { importLoaders: 1 } },
  {
    loader: "postcss-loader",
    options: {
      postcssOptions: {
        plugins: ["postcss-preset-env"],
      },
    },
  },
  "sass-loader",
];

const productionConfig: Configuration = {
  mode: "production",
  devtool: "source-map",
  externals: {
    react: "React",
    "react-dom": "ReactDOM",
  },
  plugins: [new CleanWebpackPlugin(), new MiniCssExtractPlugin()],
  module: {
    rules: [
      {
        test: stylesRegex,
        use: [MiniCssExtractPlugin.loader, ...commonStyleLoaders],
      },
    ],
  },
  optimization: {
    minimizer: [`...`, new CssMinimizerPlugin()],
  },
};

const developmentConfig: Configuration = {
  mode: "development",
  devtool: "inline-source-map",
  module: {
    rules: [
      {
        test: stylesRegex,
        use: ["style-loader", ...commonStyleLoaders],
      },
    ],
  },
  plugins: [new BundleAnalyzerPlugin()],
};

const ciConfig: Configuration = {
  mode: "development",
  module: {
    rules: [
      {
        test: stylesRegex,
        use: ["style-loader", ...commonStyleLoaders],
      },
    ],
  },
};

type Config = {
  WEBPACK_BUNDLE?: boolean;
  WEBPACK_BUILD?: boolean;
  WEBPACK_SERVE?: boolean;
  production?: boolean;
  dev?: boolean;
  ci?: boolean;
};

module.exports = (config: Config) => {
  if (config.production) {
    return merge(commonConfig, productionConfig);
  }

  if (config.ci) {
    return merge(commonConfig, ciConfig);
  }

  if (config.dev) {
    return merge(commonConfig, developmentConfig);
  }

  throw new Error("No matching configuration was found!");
};