transportMode: 'ws' interferes with proxy { ws: true }

[joonas-lahtinen]

• Operating System: any
• Node Version: any
• NPM Version: any
• webpack Version: any
• webpack-dev-server Version: any
• Browser: any

• This is a bug
• This is a modification request

Code

// webpack.config.js
...
devServer: {
  transportMode: 'ws',
  proxy: {
    '/api': {
      target: 'http://localhost:8888',
      ws: true,
    },
  },
},
...

Expected Behavior

Proxying Websockets works similar to transportMode: 'sockjs'

Actual Behavior

Websocket connections get closed with 400 Bad Request error.

For Bugs; How can we reproduce the behavior?

Simultaneously enable transportMode: 'ws' and proxy: { ws: true }

[hiroppy]

fixed by #2311, thank!