new StatsWriterPlugin({
    fields: ['assets'],
    filename: 'manifest.json',
    transform(stats) {
        const manifest = {};
        stats.assets.map(asset => asset.name)
            .sort()
            .forEach((file) => {
                manifest[file.replace(/\.[a-f0-9]{10}\./, '.')] = file;
                                               // 10 is length of hash
            });
        return JSON.stringify(manifest, null, 2) + '\n';
    }
})

   new StatsWriterPlugin({
      fields  : ['assetsByChunkName', 'assets'],
      filename: 'webpack-manifest.json',
      transform: function(stats) {
         const manifest = {};
         stats.assets.map(asset => asset.name)
            .sort()
            .forEach((file) => {
               // matches anything between two dots `.` such as app.bundle.636876e2051c910a7ef8.js,
               // app.chunk.636876e2051c910a7ef8.js, app.style.636876e2051c910a7ef8.css or
               // app.636876e2051c910a7ef8.js, but don't match the `.bundle.`, `.chunk.`, or `.style.`
               let regEx = /[^.]+\.(?=[^.]+$)/gmi;
               let passTest = regEx.test(file);
               let key = file.replace(regEx, '');

               // remove any leading `/`
               regEx = /^\//gmi;
               key = key.replace(regEx, '');
               // console.log(file, passTest, key);

               manifest[key] = file;
            });

         return JSON.stringify(manifest, null, 2) + '\n';
      }
   }),

static_file_mapping = {};
config = {
  plugins: [
    new CopyPlugin([{
            from: {
                glob: 'static/**/*.@(png|svg|jpg|gif|ico)',
                dot: false,
                noext: false,
            },
            to: '[contenthash].[ext]',
            // flatten: true
            transformPath(targetPath, absosutePath) {
                relative_path = path.relative(
                    path.resolve(root_dir),
                    absosutePath)
                static_file_mapping[relative_path] = targetPath;
                return targetPath;
            }
    }]),
    new ManifestPlugin({
      assets: static_file_mapping,
    })
  ]
}