Added babel-helper-split-export-declaration (#7313)

packages/babel-plugin-transform-classes/src/index.js

@@ -2,6 +2,7 @@ import LooseTransformer from "./loose";
 import VanillaTransformer from "./vanilla";
 import annotateAsPure from "@babel/helper-annotate-as-pure";
 import nameFunction from "@babel/helper-function-name";
+import splitExportDeclaration from "@babel/helper-split-export-declaration";
 import { types as t } from "@babel/core";
 import globals from "globals";
 
@@ -24,19 +25,7 @@ export default function(api, options) {
     visitor: {
       ExportDefaultDeclaration(path) {
         if (!path.get("declaration").isClassDeclaration()) return;
-
-        const { node } = path;
-        const ref =
-          node.declaration.id || path.scope.generateUidIdentifier("class");
-        node.declaration.id = ref;
-
-        // Split the class declaration and the export into two separate statements.
-        path.replaceWith(node.declaration);
-        path.insertAfter(
-          t.exportNamedDeclaration(null, [
-            t.exportSpecifier(t.cloneNode(ref), t.identifier("default")),
-          ]),
-        );
+        splitExportDeclaration(path);
       },
 
       ClassDeclaration(path) {