Make uglify less aggressive

Author: Ives van Hoorne

config/webpack.prod.js

@@ -29,21 +29,19 @@ module.exports = merge(commonConfig, {
       debug: false,
     }),
     new webpack.optimize.UglifyJsPlugin({
-      beautify: false,
       compress: {
-        warnings: true,
-        screw_ie8: true,
-        conditionals: true,
-        unused: true,
-        comparisons: true,
-        sequences: true,
-        dead_code: true,
-        evaluate: true,
-        if_return: true,
-        join_vars: true,
+        warnings: false,
+        // Disabled because of an issue with Uglify breaking seemingly valid code:
+        // https://github.com/facebookincubator/create-react-app/issues/2376
+        // Pending further investigation:
+        // https://github.com/mishoo/UglifyJS2/issues/2011
+        comparisons: false,
       },
       output: {
         comments: false,
+        // Turned on because emoji and regex is not minified properly using default
+        // https://github.com/facebookincubator/create-react-app/issues/2488
+        ascii_only: true,
       },
       sourceMap: true,
     }),