Migrate fbEmployee

Summary: _typescript_

Reviewed By: jknoxville

Differential Revision: D16827958

fbshipit-source-id: f2ab616b2682ede7da6c1e401fcc6d0644a1b960

src/utils/fbEmployee.tsx

@@ -0,0 +1,25 @@
+/**
+ * Copyright 2019-present Facebook.
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ * @format
+ */
+
+import util from 'util';
+const exec = util.promisify(require('child_process').exec);
+
+const cmd = 'klist --json';
+const endWith = '@THEFACEBOOK.COM';
+
+export async function isFBEmployee(): Promise<boolean> {
+  return exec(cmd).then(
+    (stdobj: {stderr: string; stdout: string}) => {
+      const principal = String(JSON.parse(stdobj.stdout).principal);
+
+      return principal.endsWith(endWith);
+    },
+    (_err: Error) => {
+      return false;
+    },
+  );
+}