From 914eb761e89d32e13ef12db2df255783ff327471 Mon Sep 17 00:00:00 2001
From: Bryce Kalow <bryce@clerk.dev>
Date: Thu, 9 May 2024 16:23:58 -0500
Subject: [PATCH] fix(clerk-js): Handle single part hostnames in
 getCookieDomain()

---
 .changeset/eighty-pens-chew.md                               | 5 +++++
 .../src/utils/cookies/__tests__/getCookieDomain.test.ts      | 4 ++++
 packages/clerk-js/src/utils/cookies/getCookieDomain.ts       | 5 +++++
 3 files changed, 14 insertions(+)
 create mode 100644 .changeset/eighty-pens-chew.md

diff --git a/.changeset/eighty-pens-chew.md b/.changeset/eighty-pens-chew.md
new file mode 100644
index 00000000000..38b0fa17236
--- /dev/null
+++ b/.changeset/eighty-pens-chew.md
@@ -0,0 +1,5 @@
+---
+'@clerk/clerk-js': patch
+---
+
+Fix a bug where client_uat domain detection would not handle hostnames with a single part. This impacts locally defined custom hostnames used as aliases.
diff --git a/packages/clerk-js/src/utils/cookies/__tests__/getCookieDomain.test.ts b/packages/clerk-js/src/utils/cookies/__tests__/getCookieDomain.test.ts
index f9a8b6457f7..5f2b335f22e 100644
--- a/packages/clerk-js/src/utils/cookies/__tests__/getCookieDomain.test.ts
+++ b/packages/clerk-js/src/utils/cookies/__tests__/getCookieDomain.test.ts
@@ -47,6 +47,10 @@ describe('getCookieDomain', () => {
     }
   });
 
+  it('handles custom hosts defined locally', () => {
+    expect(getCookieDomain('bryce-local')).toBe('bryce-local');
+  });
+
   it('returns undefined if the domain could not be determined', () => {
     const handler: CookieHandler = {
       get: jest.fn().mockReturnValue(undefined),
diff --git a/packages/clerk-js/src/utils/cookies/getCookieDomain.ts b/packages/clerk-js/src/utils/cookies/getCookieDomain.ts
index e7aa37331a8..492c2beab12 100644
--- a/packages/clerk-js/src/utils/cookies/getCookieDomain.ts
+++ b/packages/clerk-js/src/utils/cookies/getCookieDomain.ts
@@ -20,6 +20,11 @@ export function getCookieDomain(hostname = window.location.hostname, cookieHandl
 
   const hostnameParts = hostname.split('.');
 
+  // Account for custom hosts defined locally, e.g. 127.0.0.1 -> local-app
+  if (hostnameParts.length === 1) {
+    return hostname;
+  }
+
   // we know for sure that the first entry is definitely a TLD, skip it
   for (let i = hostnameParts.length - 2; i >= 0; i--) {
     const eTLD = hostnameParts.slice(i).join('.');