Proxying websocket leads to immediate closure on the server side

[jdalrymple]

I have a nuxt config using the proxy settings like:

      '/wsapi/v1': {
        target: 'ws://localhost:8081'
        changeOrigin: true,
        rewrite: (path) => path.replace(/^\/wsapi\/v1/, ''),
        ws: true,
      },

I then make a client side websocket connection:

const socket = new WebSocket('ws://localhost:8080/wsapi/v1/endpoint')

This successfully flows through the proxy to the server endpoint located at: ws://localhost:8081/endpoint, however, the server seeings the socket connection in a closed immediately - ready state (3).

For the record, the server side handler is a koa application using the koa-websockets middleware. When tested without the proxy middleware, everything is fine. Only when i include the proxy, does it have this behaviour.

Im not sure if I'm missing a setting on the proxy side, or if i should be handling it differently on the server side. Any suggestions would be amazing!