Source Map Loader

// webpack.config.js
module.exports = {
  module: {
    rules: [
      {
        test: /\.js$/,
        enforce: "pre",
        use: ["source-map-loader"],
      },
    ],
  },
};

// webpack.config.js
module.exports = {
  module: {
    rules: [
      {
        test: /\.js$/,
        enforce: "pre",
        use: ["source-map-loader"],
      },
    ],
  },
};

// webpack.config.js
module.exports = {
  module: {
    rules: [
      {
        test: /\.js$/,
        enforce: "pre",
        use: [
          {
            loader: "source-map-loader",
            options: {
              filterSourceMappingUrl: (url, resourcePath) => {
                // Skip broken source maps
                if (/broken-source-map\.js$/i.test(url)) {
                  return false;
                }
                // Keep source mapping URLs for specific files
                if (/important-file\.js$/i.test(resourcePath)) {
                  return "skip";
                }
                return true; // Process normally
              },
            },
          },
        ],
      },
    ],
  },
};

/**
 * Main webpack loader function that extracts source maps from JavaScript files
 * This function operates within webpack's loader context
 * @param {string} input - The source code content
 * @param {object} inputMap - Existing input source map (optional)
 * @returns {void} - Uses webpack callback (this.async()) to return results asynchronously
 */
async function loader(input, inputMap);

interface LoaderOptions {
  /**
   * Function to control sourceMappingURL comment behavior
   * @param {string} sourceMappingURL - The URL from the sourceMappingURL comment
   * @param {string} resourcePath - Path to the current resource being processed
   * @returns {boolean | string} - Action to take for this source map
   */
  filterSourceMappingUrl?: (sourceMappingURL: string, resourcePath: string) => boolean | string;
}

/**
 * Filter function for controlling sourceMappingURL behavior
 * @param {string} sourceMappingURL - The URL extracted from sourceMappingURL comment
 * @param {string} resourcePath - Absolute path to the file being processed
 * @returns {boolean | string} - Action to take:
 *   - true or "consume": Process source map and remove comment (default)
 *   - false or "remove": Skip source map processing but remove comment
 *   - "skip": Skip source map processing and keep comment
 */
type FilterSourceMappingUrl = (sourceMappingURL: string, resourcePath: string) => boolean | "consume" | "remove" | "skip";

// Skip processing for specific URLs
filterSourceMappingUrl: (url, resourcePath) => {
  if (/broken-source-map\.js$/i.test(url)) {
    return false; // Remove comment but don't process
  }
  return true; // Process normally
}

// Keep source mapping URLs for debugging
filterSourceMappingUrl: (url, resourcePath) => {
  if (/debug-build\.js$/i.test(resourcePath)) {
    return "skip"; // Keep comment and don't process
  }
  return "consume"; // Process and remove comment
}