Transform modules in test

Author: Timer

packages/babel-preset-react-app/index.js

@@ -102,6 +102,7 @@ module.exports = function(api, opts) {
       isEnvTest &&
         // Transform dynamic import to require
         require('babel-plugin-transform-dynamic-import').default,
+      isEnvTest && require('@babel/plugin-transform-modules-commonjs'),
     ].filter(Boolean),
   };
 };

packages/babel-preset-react-app/package.json

@@ -15,6 +15,7 @@
     "@babel/plugin-proposal-class-properties": "7.0.0-beta.34",
     "@babel/plugin-syntax-dynamic-import": "^7.0.0-beta.34",
     "@babel/plugin-transform-classes": "7.0.0-beta.34",
+    "@babel/plugin-transform-modules-commonjs": "^7.0.0-beta.34",
     "@babel/plugin-transform-react-constant-elements": "7.0.0-beta.34",
     "@babel/plugin-transform-react-display-name": "7.0.0-beta.34",
     "@babel/plugin-transform-react-jsx": "7.0.0-beta.34",