Babel 7 disabled code highlighting by default 😢 (#3849)

packages/react-scripts/config/webpack.config.dev.js

@@ -194,6 +194,7 @@ module.exports = {
                   // It enables caching results in ./node_modules/.cache/babel-loader/
                   // directory for faster rebuilds.
                   cacheDirectory: true,
+                  highlightCode: true,
                 },
               },
             ],
@@ -215,6 +216,7 @@ module.exports = {
                     require.resolve('babel-preset-react-app/dependencies'),
                   ],
                   cacheDirectory: true,
+                  highlightCode: true,
                 },
               },
             ],

packages/react-scripts/config/webpack.config.prod.js

@@ -199,6 +199,7 @@ module.exports = {
                   presets: [require.resolve('babel-preset-react-app')],
                   // @remove-on-eject-end
                   compact: true,
+                  highlightCode: true,
                 },
               },
             ],
@@ -220,6 +221,7 @@ module.exports = {
                     require.resolve('babel-preset-react-app/dependencies'),
                   ],
                   cacheDirectory: true,
+                  highlightCode: true,
                 },
               },
             ],