add WS support?

[stevenpollack]

Context

I love using nock for my HTTP server mocking, and I'd love to use it for a WS project I'm working on. I was hoping it could intercept messages (at least from) the websocket server.

Has the feature been requested before?

This was discussed in #129.

If the feature request is accepted, would you be willing to submit a PR?

Sadly, I don't think I'm skilled enough to implement this on my own, but I'd be willing to help if someone could give me guidance.

[gr2m]

I hope to finally have the time to tackle the decomposition of nock into smaller module as mentioned in #129 (comment). Once we have that we might look into an alternative intercept module that will work with websockets.

If anyone knows of prior work for websocket mocking, please share!

[stevenpollack]

I'm happy to help however I can!

[izzqz]

+1 am Interested in feature

[gr2m]

A good place to start is to discuss a "dream API". Gather your use cases and make up the best possible APIs to make them possible. Then we have something we can work towards.

[izzqz]

I suggest simply adding a pipeline function for the various sub-protocols in websockets or HTTP. Here's an example for a node:

import nock from 'nock';
import WebSocket, { createWebSocketStream } from 'ws';

const ws = new WebSocket('wss://echo.websocket.org/', {
    origin: 'https://websocket.org',
});

const duplexWebSocket = createWebSocketStream(ws, { encoding: 'utf8' });

// nock will intercept request, check header and pipe to websocket server
nock('https://websocket.org')
    .matchHeader('X-MBX-APIKEY', 'foobar')
    .pipe(duplexWebSocket);

duplexWebSocket.pipe(process.stdout);

With this nock API, we can create any mocking implementation.

[gr2m]

This looks great! How would like to define mocks beyond just headers?