webpack.config.js

const fs = require("fs");
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const webpack = require("webpack");

const bootstrapPath =
  __dirname + "/node_modules/bootstrap-sass/assets/stylesheets";

// A custom node-sass importer that removes some unwanted rules from _normalize.scss.
function importerWhichRewritesBootstrapNormalizeScss(url, prev, done) {
  if (url != "bootstrap/normalize") {
    done(null);
    return;
  }

  var originalPath = bootstrapPath + "/bootstrap/_normalize.scss";
  fs.readFile(originalPath, "utf8", (err, data) => {
    if (err) return done(err);

    function remove(what) {
      if (!data.includes(what)) throw Error(`"${what}" not found`);
      data = data.replace(what, "");
    }

    // Don't use pointer cursor on buttons.
    // http://lists.w3.org/Archives/Public/public-css-testsuite/2010Jul/0024.html
    remove("cursor: pointer; // 3");

    // Don't inherit color and font on inputs and selects.
    remove("color: inherit; // 1");
    remove("font: inherit; // 2");

    done({ contents: data });
  });
}

const outputPath = __dirname + "/votrfront/static";

// A plugin which writes the current status to votrfront/static/status.
// - "busy" during compilation
// - "failed" on errors
// - "ok_dev" or "ok_prod" on success
// votrfront/front.py reads the status to check if it can serve the page.
function StatusFilePlugin(mode) {
  this.apply = function (compiler) {
    function writeStatus(content, callback) {
      fs.mkdir(outputPath, function (err) {
        if (err && err.code != "EEXIST") return callback(err);
        fs.writeFile(outputPath + "/status", content + "\n", "utf8", callback);
      });
    }

    function handleRunEvent(compilationParams, callback) {
      writeStatus("busy", callback);
    }

    compiler.hooks.run.tapAsync("StatusFilePlugin", handleRunEvent);
    compiler.hooks.watchRun.tapAsync("StatusFilePlugin", handleRunEvent);
    compiler.hooks.done.tapAsync("StatusFilePlugin", (stats, callback) => {
      const status = stats.compilation.errors.length ? "failed" : "ok_" + mode;
      writeStatus(status, callback);
    });
  };
}

// A plugin which deletes old .map files. We can't use clean-webpack-plugin to
// delete *.map before every compilation, because in watch mode, if a .js file
// doesn't change then its .map file won't be regenerated.
function CleanMapFilesPlugin() {
  this.apply = function (compiler) {
    compiler.hooks.afterEmit.tapAsync(
      "CleanMapFilesPlugin",
      function (compilation, callback) {
        for (const file of fs.readdirSync(outputPath)) {
          if (
            file.match(/\.map$/) &&
            !compilation.assets[file] &&
            compilation.assets[file.replace(/\.\w+\.map$/, "")]
          ) {
            fs.unlinkSync(outputPath + "/" + file);
          }
        }
        callback();
      }
    );
  };
}

module.exports = function (env, args) {
  const mode = args.mode;

  const config = {
    entry: {
      votr: "./votrfront/js/main",
      prologue: "./votrfront/js/prologue",
    },
    output: {
      path: outputPath,
      filename: mode == "development" ? "[name].dev.js" : "[name].min.js",
      sourceMapFilename: "[file].[contenthash].map", // it seems Chrome caches source maps even if "Disable cache" is enabled
    },
    plugins: [
      new MiniCssExtractPlugin({ filename: "style.css" }),
      new StatusFilePlugin(mode == "development" ? "dev" : "prod"),
      new CleanMapFilesPlugin(),
      new webpack.ContextReplacementPlugin(/moment[/\\]locale$/, /sk/),
    ],
    resolve: {
      extensions: [".ts", ".tsx", ".js"],
    },
    module: {
      rules: [
        {
          // Without this, webpack tries to replace `define.amd` in jquery and
          // file-saver with its own definition.
          parser: { amd: false },
        },
        {
          test: /\.[tj]sx?$/,
          exclude: /node_modules/,
          loader: "ts-loader",
        },
        {
          test: /node_modules\/bootstrap-sass\//,
          loader: "imports-loader",
          options: { imports: ["default jquery jQuery"] },
        },
        {
          test: /\.scss$/,
          use: [
            MiniCssExtractPlugin.loader,
            "css-loader",
            {
              loader: "sass-loader",
              options: {
                sassOptions: {
                  includePaths: [bootstrapPath],
                  outputStyle: mode == "development" ? undefined : "compressed",
                  importer: importerWhichRewritesBootstrapNormalizeScss,
                },
              },
            },
          ],
        },
        {
          test: /\.svg$/,
          type: "asset/inline",
        },
      ],
    },
    optimization: {
      splitChunks: {
        chunks: "all",
        minSize: 0,
        name: (module, chunks, cacheGroupKey) => {
          if (cacheGroupKey !== "defaultVendors") throw Error("wat");
          if (chunks.length !== 1) throw Error("wat");
          return `vendors_${chunks[0].name}`;
        },
      },
    },
    devtool: "source-map",
    performance: {
      maxAssetSize: 750 * 1024,
      maxEntrypointSize: 750 * 1024,
    },
  };

  return config;
};