devServer websocket proxy cannot upgrade websocket connection

I’m submitting a bug report

webpack and webpack-dev-server version: webpack: 1.13.2 webpack-dev-server: 1.16.1

Please tell us about your environment: Linux Fedora 22

Current behavior: devServer websocket proxy cannot upgrade websocket connection sporadically

Expected/desired behavior: http-proxy-middleware should upgrade websocket requests always

Howto Reproduce / Setup

setup

 devServer: {
      proxy: {
        '/hyperguard/websocket/*': {
          target: 'ws://localhost:8082',
        ws: true
        }
      }
    }

http stream request

GET /hyperguard/websocket HTTP/1.1
Host: localhost:8079
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Sec-WebSocket-Version: 13
origin: http://localhost:8079
Sec-WebSocket-Extensions: permessage-deflate
Sec-WebSocket-Key: yrOcNHCvvVuGgttYgv9nzA==
Connection: keep-alive, Upgrade
Pragma: no-cache
Cache-Control: no-cache
Upgrade: websocket

http stream response getting this response only sometimes, if not the websocket connection never be established

HTTP/1.1 101 Switching Protocols
upgrade: websocket
connection: Upgrade
sec-websocket-accept: I3u4B7iakSJWk4yLd02hfn+enus=

• that issue also occurs on different platforms (ubuntu 14.04, centos7)
• restarting webpack-dev-server doesnt change anything

[SpaceK33z]

See the comment above me.

[desytech]

filed this bug on http-proxy-middleware chimurai/http-proxy-middleware#112