webpack.config.js

import webpack from 'webpack';
import TerserPlugin from "terser-webpack-plugin";
import { fileURLToPath } from "url";
import path from "path";

const __dirname = path.dirname(fileURLToPath(import.meta.url));

/**
 * Helper function to create webpack configurations.
 * @param {Object} options Options for creating a webpack target.
 * @param {string} options.name Name of output file.
 * @param {string} options.suffix Suffix of output file.
 * @param {string} options.type Type of library.
 * @param {string} options.ignoreModules The list of modules to ignore.
 * @param {string} options.externalModules The list of modules to set as external.
 * @param {Object[]} options.plugins List of plugins to use.
 * @returns {import('webpack').Configuration} One webpack target.
 */
function buildConfig({
  name = "",
  suffix = ".js",
  type = "module", // 'module' | 'commonjs'
  ignoreModules = [],
  externalModules = [],
  plugins = [],
} = {}) {
  const outputModule = type === "module";

  const alias = Object.fromEntries(
    ignoreModules.map((module) => [module, false]),
  );

  /** @type {import('webpack').Configuration} */
  const config = {
    mode: "development",
    devtool: "source-map",
    entry: {
      // [`transformers${name}`]: "./src/transformers.js",
      [`workfunction`]: "./src/work-function-entry.js",
      // [`transformers${name}.min`]: "./src/transformers.js",
    },
    output: {
      filename: `[name]${suffix}`,
      path: path.join(__dirname, "dist"),
      library: {
        type,
      },
      assetModuleFilename: "[name][ext]",
      chunkFormat: false,
      iife: true,
    },
    optimization: {
      minimize: true,
      minimizer: [
        new TerserPlugin({
          test: new RegExp(`\\.min\\${suffix}$`),

          // Do not bundle with comments.
          // See https://webpack.js.org/plugins/terser-webpack-plugin/#remove-comments for more information.
          terserOptions: {
            // output: {
            //   comments: false,
            // },
            compress: false,
            mangle: false,
          },
          extractComments: false,
        }),
      ],
      // usedExports: true,
    },
    experiments: {
      outputModule,
    },
    resolve: { 
      alias,
      fallback: {
        "fs": false,
        "tls": false,
      }
    },

    externals: externalModules,

    // Development server
    devServer: {
      static: {
        directory: __dirname,
      },
      port: 8080,
    },
    plugins,
    module: {
      rules: [
        {
  
          test: /distilbert-base-uncased-finetuned-sst-2-english|tiny-random-mistral|SmolLM2-135M-Instruct|SmolLM2-360M-Instruct|Qwen3-0.6B-ONNX|whisper\-.*/,
          type: 'asset/inline', // embed as data urls, see https://webpack.js.org/guides/asset-modules/#inlining-assets
          generator: {
            dataUrl: {
              mimetype: 'application/octet-stream',
            },
          },
        }
      ]
    }
  };

  if (outputModule) {
    config.module = {
      parser: {
        javascript: {
          importMeta: false,
        },
      },
    };
  } else {
    config.externalsType = "commonjs";
  }

  return config;
}

/**
 * Plugin to strip the "node:" prefix from module requests.
 * 
 * This is necessary to ensure both web and node builds work correctly,
 * otherwise we would get an error like:
 * ```
 * Module build failed: UnhandledSchemeError: Reading from "node:path" is not handled by plugins (Unhandled scheme).
 * Webpack supports "data:" and "file:" URIs by default.
 * You may need an additional plugin to handle "node:" URIs.
 * ```
 * 
 * NOTE: We then do not need to use the `node:` prefix in the resolve.alias configuration.
 */
class StripNodePrefixPlugin extends webpack.NormalModuleReplacementPlugin {
  constructor() {
    super(
      /^node:(.+)$/,
      resource => {
        resource.request = resource.request.replace(/^node:/, '');
      }
    );
  }
}

export default  buildConfig({
  name: ".custom",
  type: "commonjs",
  ignoreModules: [
    "onnxruntime-node",
    "onnxruntime-web",
    "sharp",
    "fs",
    "path",
    "url",
  ],
  externalModules: [
    "dcp-wasm.js",
    "dcp-ort.js",
  ],
  plugins: [
    new StripNodePrefixPlugin(),
    new webpack.BannerPlugin({
      banner: 'function workFunction(...args) {const exports = {};',
      raw: true,
      stage: webpack.Compilation.PROCESS_ASSETS_STAGE_REPORT,
    }),
    new webpack.BannerPlugin({
      banner: 'return exports.default(...args);}', // making sure we await the promise
      raw: true,
      footer: true,
      stage: webpack.Compilation.PROCESS_ASSETS_STAGE_REPORT,
    }),
  ]
});