scratch-blocks/webpack.config.js

const path = require("path");

// Base config that applies to either development or production mode.
const config = {
  entry: "./src/index.ts",
  output: {
    library: "ScratchBlocks",
    libraryTarget: "commonjs2",
    path: path.resolve(__dirname, "dist"),
    filename: "[name].js",
  },
  resolve: {
    extensions: [".ts", ".js"],
  },
  module: {
    rules: [
      {
        test: /\.ts$/,
        use: "ts-loader",
        exclude: /node_modules/,
      },
    ],
  },
  // Enable webpack-dev-server to get hot refresh of the app.
  devServer: {
    static: "./build",
  },
};

module.exports = (env, argv) => {
  if (argv.mode === "development") {
    // Set the output path to the `build` directory
    // so we don't clobber production builds.
    config.output.path = path.resolve(__dirname, "build");

    // Generate source maps for our code for easier debugging.
    // Not suitable for production builds. If you want source maps in
    // production, choose a different one from https://webpack.js.org/configuration/devtool
    config.devtool = "eval-cheap-module-source-map";

    // Include the source maps for Blockly for easier debugging Blockly code.
    config.module.rules.push({
      test: /(blockly\/.*\.js)$/,
      use: [require.resolve("source-map-loader")],
      enforce: "pre",
    });

    // Ignore spurious warnings from source-map-loader
    // It can't find source maps for some Closure modules and that is expected
    config.ignoreWarnings = [/Failed to parse source map/];
  }
  return config;
};