module.exports = {
  // Don't try to find .babelrc because we want to force this configuration.
  babelrc: false,
  presets: [
    [
      require.resolve('babel-preset-env'),
      {
        targets: {
          browsers: ['last 2 versions', 'safari >= 7'],
        },
        modules: false,
      },
    ],
    require.resolve('babel-preset-stage-0'),
    require.resolve('babel-preset-react'),
    require.resolve('babel-preset-minify'),
  ],
  plugins: [
    require.resolve('babel-plugin-transform-regenerator'),
    [
      require.resolve('babel-plugin-transform-runtime'),
      {
        helpers: true,
        polyfill: true,
        regenerator: true,
      },
    ],
  ],
};

@@ -387,24 +387,32 @@
 et-react'),%0A
+    %5B%0A  
     require.
@@ -443,16 +443,63 @@
 nify'),%0A
+      %7B%0A        mangle: false,%0A      %7D,%0A    %5D,%0A
   %5D,%0A  p

Set mangle to false in babel-preset-minify for polymer to fix static build