Fix exports is undefined (#826)

* Add allowTopLevelThis=true option for @babel/plugin-transform-modules-commonjs

Signed-off-by: Hailong Cui <ihailong@amazon.com>

* remove override babel.config.js for build

Signed-off-by: Hailong Cui <ihailong@amazon.com>

---------

Signed-off-by: Hailong Cui <ihailong@amazon.com>
(cherry picked from commit be25b8b)
Signed-off-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

babel.config.js

@@ -5,11 +5,18 @@
 
 // babelrc doesn't respect NODE_PATH anymore but using require does.
 // Alternative to install them locally in node_modules
-module.exports = {
-  presets: [require("@babel/preset-env"), require("@babel/preset-react"), require("@babel/preset-typescript")],
-  plugins: [
-    [require("@babel/plugin-transform-runtime"), { regenerator: true }],
-    require("@babel/plugin-proposal-class-properties"),
-    require("@babel/plugin-proposal-object-rest-spread"),
-  ],
+module.exports = function (api) {
+  // ensure env is test so that this config won't impact build or dev server
+  if (api.env("test")) {
+    return {
+      presets: [require("@babel/preset-env"), require("@babel/preset-react"), require("@babel/preset-typescript")],
+      plugins: [
+        [require("@babel/plugin-transform-runtime"), { regenerator: true }],
+        require("@babel/plugin-proposal-class-properties"),
+        require("@babel/plugin-proposal-object-rest-spread"),
+        [require("@babel/plugin-transform-modules-commonjs"), { allowTopLevelThis: true }],
+      ],
+    };
+  }
+  return {};
 };