How to test subscriptions?

[Sam-Kruglov]

I'm getting "socket closed" with or without config with import { ws } from 'msw'.

Piece of my .storybook/preview.tsx:

parameters: {
  msw: {
    handlers: {
      graphql: createHandlerFromSchema(...)
    }
  },

Looks like createHandlerFromSchema already integrates with MSW but not for subscriptions, is that a bug? And somehow even if I try to configure msw.ws.link(...) it still has no effect. Either way please add an example to this repo

storybook params come from https://github.com/mswjs/msw-storybook-addon

I set up resolver for subscription query via rxjs.Subject that gets kicked off by calling a mutation (couldn't use PubSub from your demo because it has no built-in impl for browser and I already have rxjs). But I don't think that matters.

[jerelmiller]

Hey @Sam-Kruglov 👋

Subscriptions aren't yet officially supported in this library. As stated in the README:

This library currently supports incremental delivery features @defer and @stream out of the box, with plans to support subscriptions over multipart HTTP as well as other transports such as WebSockets, mswjs/msw#2010.

At the time this library was created, MSW didn't quite support websockets so we couldn't support them in this library either. We've been hard at work on Apollo Client 4.0 in the time that websocket support was added to MSW so we haven't had the capacity to implement it in this library yet.

Once 4.0 releases (currently slated for end of July), we plan to give this library more attention, including proper subscription support. Sorry for the confusion! Hope this helps.

[Sam-Kruglov]

Missed that, no problem, thanks!