From a061f460e5ed172ba96053acf01e68838f803856 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 6 Apr 2026 03:55:56 +0000
Subject: [PATCH] fix: early sync return in getLocalhostAddressIfDiffersFromDNS
 when dns order is verbatim

Agent-Logs-Url: https://github.com/vitejs/vite/sessions/5548c174-2a7f-4cd2-b3df-cce35e3494c5

Co-authored-by: sapphi-red <49056869+sapphi-red@users.noreply.github.com>
---
 packages/vite/src/node/utils.ts | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/packages/vite/src/node/utils.ts b/packages/vite/src/node/utils.ts
index f8c7154a879b39..8c3bbb2cd79385 100644
--- a/packages/vite/src/node/utils.ts
+++ b/packages/vite/src/node/utils.ts
@@ -922,17 +922,21 @@ export function unique<T>(arr: T[]): T[] {
  * Even if defaultResultOrder is `ipv4first`, `dns.lookup` result maybe same.
  * For example, when IPv6 is not supported on that machine/network.
  */
-export async function getLocalhostAddressIfDiffersFromDNS(): Promise<
-  string | undefined
-> {
-  const [nodeResult, dnsResult] = await Promise.all([
+export function getLocalhostAddressIfDiffersFromDNS():
+  | Promise<string | undefined>
+  | undefined {
+  if (dns.getDefaultResultOrder() === 'verbatim') {
+    return undefined
+  }
+  return Promise.all([
     dns.lookup('localhost'),
     dns.lookup('localhost', { verbatim: true }),
-  ])
-  const isSame =
-    nodeResult.family === dnsResult.family &&
-    nodeResult.address === dnsResult.address
-  return isSame ? undefined : nodeResult.address
+  ]).then(([nodeResult, dnsResult]) => {
+    const isSame =
+      nodeResult.family === dnsResult.family &&
+      nodeResult.address === dnsResult.address
+    return isSame ? undefined : nodeResult.address
+  })
 }
 
 export function diffDnsOrderChange(