diff --git a/Build/lib/stable-sort-domain.test.ts b/Build/lib/stable-sort-domain.test.ts
new file mode 100644
index 00000000..6f4f0f2a
--- /dev/null
+++ b/Build/lib/stable-sort-domain.test.ts
@@ -0,0 +1,51 @@
+// eslint-disable-next-line import-x/no-unresolved -- bun
+import { describe, expect, it } from 'bun:test';
+
+import { sortDomains } from './stable-sort-domain';
+import { getGorhillPublicSuffixPromise } from './get-gorhill-publicsuffix';
+
+describe('sortDomains', () => {
+  it('basic', async () => {
+    const gorhill = await getGorhillPublicSuffixPromise();
+
+    expect(
+      sortDomains([
+        '.s3-website.ap-northeast-3.amazonaws.com',
+        '.s3.dualstack.ap-south-1.amazonaws.com',
+        '.s3-website.af-south-1.amazonaws.com'
+      ], gorhill)
+    ).toStrictEqual(
+      sortDomains([
+        '.s3.dualstack.ap-south-1.amazonaws.com',
+        '.s3-website.ap-northeast-3.amazonaws.com',
+        '.s3-website.af-south-1.amazonaws.com'
+      ], gorhill)
+    );
+
+    expect(
+      sortDomains([
+        '.s3-website-us-west-2.amazonaws.com',
+        '.s3-1.amazonaws.com'
+      ], gorhill)
+    ).toStrictEqual(
+      sortDomains([
+        '.s3-1.amazonaws.com',
+        '.s3-website-us-west-2.amazonaws.com'
+      ], gorhill)
+    );
+
+    expect(
+      sortDomains([
+        '.s3-deprecated.us-west-2.amazonaws.com',
+        '.s3-accesspoint.dualstack.us-west-2.amazonaws.com',
+        '.s3.dualstack.us-west-2.amazonaws.com'
+      ], gorhill)
+    ).toStrictEqual(
+      sortDomains([
+        '.s3-accesspoint.dualstack.us-west-2.amazonaws.com',
+        '.s3.dualstack.us-west-2.amazonaws.com',
+        '.s3-deprecated.us-west-2.amazonaws.com'
+      ], gorhill)
+    );
+  });
+});