webpack.config.js

const path = require('node:path')

/**
 * @import {Configuration, RuleSetRule} from "webpack"
 */

/**
 * Base config that applies to either development or production mode.
 * @satisfies {Configuration}
 */
const config = {
  entry: './src/index.ts',
  experiments: {
    outputModule: true,
  },
  output: {
    library: { type: 'module' },
    path: path.resolve(__dirname, 'dist'),
    filename: '[name].mjs',
    clean: true,
  },
  resolve: {
    extensions: ['.ts', '.js'],
  },
  module: {
    rules: /** @type {RuleSetRule[]} */ ([
      {
        test: /\.ts$/,
        use: 'ts-loader',
        exclude: /node_modules/,
      },
    ]),
  },
  // Enable webpack-dev-server to get hot refresh of the app.
  devServer: {
    static: './build',
  },
  devtool: /** @type {Configuration["devtool"]} */ (false),
  ignoreWarnings: /** @type {Configuration["ignoreWarnings"]} */ ([]),
}

/**
 * @returns {Configuration}
 */
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
}