Implements export statement rewriting

Author: lukejacksonn

.babelrc.js

@@ -22,6 +22,7 @@ module.exports = {
           return {
             visitor: {
               ImportDeclaration: function(path, state) {
+                if (!path.node.source) return;
                 var source = path.node.source.value;
                 if (source.match(/^\.{0,2}\//) && !source.endsWith('.es.js')) {
                   path.replaceWith(
@@ -32,6 +33,19 @@ module.exports = {
                   );
                 }
               },
+              ExportNamedDeclaration: function(path, state) {
+                if (!path.node.source) return;
+                const source = path.node.source.value;
+                if (source.match(/^\.{0,2}\//) && !source.endsWith('.es.js')) {
+                  path.replaceWith(
+                    types.exportNamedDeclaration(
+                      path.node.declaration,
+                      path.node.specifiers,
+                      types.stringLiteral(source + '.es.js'),
+                    ),
+                  );
+                }
+              },
             },
           };
         },