fix: close HotChannel on environment close (#18206)

packages/vite/src/node/server/environment.ts

@@ -31,6 +31,7 @@ import {
   createEnvironmentPluginContainer,
 } from './pluginContainer'
 import type { RemoteEnvironmentTransport } from './environmentTransport'
+import { isWebSocketServer } from './ws'
 
 export interface DevEnvironmentContext {
   hot: false | HotChannel
@@ -206,6 +207,8 @@ export class DevEnvironment extends BaseEnvironment {
     await Promise.allSettled([
       this.pluginContainer.close(),
       this.depsOptimizer?.close(),
+      // WebSocketServer is independent of HotChannel and should not be closed on environment close
+      isWebSocketServer in this.hot ? this.hot.close() : Promise.resolve(),
       (async () => {
         while (this._pendingRequests.size > 0) {
           await Promise.allSettled(

packages/vite/src/node/server/hmr.ts

@@ -115,7 +115,7 @@ export interface HotChannel {
   /**
    * Disconnect all clients, called when server is closed or restarted.
    */
-  close(): void
+  close(): Promise<unknown> | void
 }
 /** @deprecated use `HotChannel` instead */
 export type HMRChannel = HotChannel

packages/vite/src/node/server/ws.ts

@@ -31,7 +31,10 @@ export type WebSocketCustomListener<T> = (
   client: WebSocketClient,
 ) => void
 
+export const isWebSocketServer = Symbol('isWebSocketServer')
+
 export interface WebSocketServer extends HotChannel {
+  [isWebSocketServer]: true
   /**
    * Listen on port and host
    */
@@ -88,6 +91,7 @@ export function createWebSocketServer(
 ): WebSocketServer {
   if (config.server.ws === false) {
     return {
+      [isWebSocketServer]: true,
       get clients() {
         return new Set<WebSocketClient>()
       },
@@ -234,6 +238,7 @@ export function createWebSocketServer(
   let bufferedError: ErrorPayload | null = null
 
   return {
+    [isWebSocketServer]: true,
     listen: () => {
       wsHttpServer?.listen(port, host)
     },