source-map-loader

extracts inlined source map and offers it to webpack

source map loader for webpack

Extracts SourceMaps for source files that as added as sourceMappingURL comment.

Documentation: Using loaders

module.exports = {
  module: {
    preLoaders: [
      {
        test: /\.js$/,
        loader: "source-map-loader"
      }
    ]
  }
};

This extracts all SourceMaps from all files. That's no so performance-wise so you may only want to apply the loader to relevant files.

MIT (http://www.opensource.org/licenses/mit-license.php)