From a32c1828768fb3d03b818c808682a83a42d9d6c3 Mon Sep 17 00:00:00 2001
From: David-Emmanuel DIVERNOIS <david-emmanuel.divernois@amadeus.com>
Date: Tue, 16 May 2023 17:01:52 +0200
Subject: [PATCH] feat: allow using vite as a proxy for another vite server

---
 packages/vite/src/node/server/middlewares/proxy.ts |  8 +++-----
 packages/vite/src/node/server/ws.ts                | 11 ++++++++++-
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/packages/vite/src/node/server/middlewares/proxy.ts b/packages/vite/src/node/server/middlewares/proxy.ts
index 66f99f94f0609d..ae289a8f8e9776 100644
--- a/packages/vite/src/node/server/middlewares/proxy.ts
+++ b/packages/vite/src/node/server/middlewares/proxy.ts
@@ -4,7 +4,6 @@ import httpProxy from 'http-proxy'
 import type { Connect } from 'dep-types/connect'
 import type { HttpProxy } from 'dep-types/http-proxy'
 import colors from 'picocolors'
-import { HMR_HEADER } from '../ws'
 import { createDebugger } from '../../utils'
 import type { CommonServerOptions, ResolvedConfig } from '../..'
 
@@ -103,10 +102,9 @@ export function proxyMiddleware(
         if (doesProxyContextMatchUrl(context, url)) {
           const [proxy, opts] = proxies[context]
           if (
-            (opts.ws ||
-              opts.target?.toString().startsWith('ws:') ||
-              opts.target?.toString().startsWith('wss:')) &&
-            req.headers['sec-websocket-protocol'] !== HMR_HEADER
+            opts.ws ||
+            opts.target?.toString().startsWith('ws:') ||
+            opts.target?.toString().startsWith('wss:')
           ) {
             if (opts.rewrite) {
               req.url = opts.rewrite(url)
diff --git a/packages/vite/src/node/server/ws.ts b/packages/vite/src/node/server/ws.ts
index 61d989080e7573..e1278959fedb27 100644
--- a/packages/vite/src/node/server/ws.ts
+++ b/packages/vite/src/node/server/ws.ts
@@ -1,3 +1,4 @@
+import path from 'node:path'
 import type { Server } from 'node:http'
 import { STATUS_CODES, createServer as createHttpServer } from 'node:http'
 import type { ServerOptions as HttpsServerOptions } from 'node:https'
@@ -101,9 +102,17 @@ export function createWebSocketServer(
   const host = (hmr && hmr.host) || undefined
 
   if (wsServer) {
+    let hmrBase = config.base
+    const hmrPath = hmr ? hmr.path : undefined
+    if (hmrPath) {
+      hmrBase = path.posix.join(hmrBase, hmrPath)
+    }
     wss = new WebSocketServerRaw({ noServer: true })
     wsServer.on('upgrade', (req, socket, head) => {
-      if (req.headers['sec-websocket-protocol'] === HMR_HEADER) {
+      if (
+        req.headers['sec-websocket-protocol'] === HMR_HEADER &&
+        req.url === hmrBase
+      ) {
         wss.handleUpgrade(req, socket as Socket, head, (ws) => {
           wss.emit('connection', ws, req)
         })