Versions:

• Minecraft: 1.12.2
• CC: Tweaked: 1.82.2
• Modpack: FTB Ultimate Reloaded

Reproduction steps

• Create a websocket server that does not reply
• Connect to server in CC
• Call ws.receive()
• Wait forever
• Observe that CC will never return
• Close server
• Observe that CC is still waiting to receive, even though the server is closed.

Implement

There needs to be a websocket_timeout event I believe, and this needs to be captured in the receive function, the receive function should also take an optional timeout argument.

I do believe there is already a websocket_close event, but it seems that websocket.receive does not wait for it. It should.

Similar things could be said for send() I imagine, but I don't have a producible issue there.

Regarding creating a websocket server that does not reply. Here is a minimal setup.

• Install Node.js
• Create a directory somewhere for a project, change in to that directory
• npm i ws
• Create index.js and add this source:

const ws = require('ws')
const wss = new ws.Server({
  host: '0.0.0.0',
  port: 80
}, () => console.log('server started'))
.on('connection', (client) => { 
  console.log('client connected')
  client.on('close', (code, reason) => {
    console.log('client disconnected', code, reason)
  }).on('message', (msg) => {
    console.log('message', msg)
  })
})
.on('error', (error) => console.log('server error', error))

• Run server node index.js

On the client side, just connect, and then receive.