add: unit and integration testing

app/node_modules/babel-plugin-jest-hoist/build/index.d.ts

@@ -0,0 +1,15 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import {PluginObj, babelCore} from '@babel/core';
+import {Identifier} from '@babel/types';
+
+declare function jestHoist(babel: babelCore): PluginObj<{
+  declareJestObjGetterIdentifier: () => Identifier;
+  jestObjGetterIdentifier?: Identifier;
+}>;
+export default jestHoist;