From 4848e413a1db81957e2e4a263d1bd0c5a733ac56 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=EC=9D=B4=EC=B1=84=EC=A4=80=20-=20CJ=20Lee?=
 <chaejunlee@knu.ac.kr>
Date: Mon, 24 Jul 2023 17:01:14 +0900
Subject: [PATCH] fix(proxy): handle error when proxy itself errors (#13929)

---
 packages/vite/src/node/server/middlewares/proxy.ts | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/packages/vite/src/node/server/middlewares/proxy.ts b/packages/vite/src/node/server/middlewares/proxy.ts
index 6b282e0afea05b..bf658a9ea7474f 100644
--- a/packages/vite/src/node/server/middlewares/proxy.ts
+++ b/packages/vite/src/node/server/middlewares/proxy.ts
@@ -52,8 +52,17 @@ export function proxyMiddleware(
 
     proxy.on('error', (err, req, originalRes) => {
       // When it is ws proxy, res is net.Socket
-      const res = originalRes as http.ServerResponse | net.Socket
-      if ('req' in res) {
+      // originalRes can be falsy if the proxy itself errored
+      const res = originalRes as http.ServerResponse | net.Socket | undefined
+      if (!res) {
+        config.logger.error(
+          `${colors.red(`http proxy error: ${err.message}`)}\n${err.stack}`,
+          {
+            timestamp: true,
+            error: err,
+          },
+        )
+      } else if ('req' in res) {
         config.logger.error(
           `${colors.red(`http proxy error at ${originalRes.req.url}:`)}\n${
             err.stack