An error has occured for subscription 'chatMessageAdded' #

[akaNightmare]

Hello, I receive next error message from backend
{message: "Cannot read property 'then' of undefined"}

I believe the issue related to https://github.com/graphql/graphql-js/releases/tag/v0.11.0

Thanks.

[kachkaev]

Looks like I'm also facing this – the subscriptions stopped working after a recent upgrade. Rolling back to "graphql": "0.10.5" helped. How about downgrading this dependency until a proper bugfix has been found?

It is likely that this breaking change causes the issue: graphql/graphql-js#918 I guess that things like withFilter in graphql-subscriptions need an upgrade too, because subscribe is now expected to be a Promise.

[nowzig]

I can confirm this problem. It works with "graphql": "0.10.5" but not with "graphql": "0.11.*"

[dangerdespain]

+1 I'm experience this issue with 0.11.* as well. Downgrading to 0.10.5 resolves the issue.

[luizstacio]

+1 I'm experience this issue too. Downgrading resolves.

[kachkaev]

Ping @stubailo @martijnwalraven. It is likely that all the apollo newcomers are installing a broken version – might be crucial to fix ASAP.

[AkimaLunar]

This is still an issue for me and downgrading to 0.10.5 resolves it. Ideally, I'd like to use 0.11.

[martijnwalraven]

@AkimaLunar: What version of graphql-subscriptions are you using?

[AkimaLunar]

@martijnwalraven It's "graphql-subscriptions": "^0.4.4"

[martijnwalraven]

@AkimaLunar: The latest version of graphql-subscriptions is 0.5.5, so I believe upgrading that should solve this.

[perrosnk]

Any updates on this?
I am getting an error: Subscription must return Async Iterable. Received: [object Object]

[martijnwalraven]

@perrosnk This seems unrelated to this issue (which should be solved in recent versions of graphql-subscriptions). Are you in fact returning an AsyncIterable from the subscribe function in your schema?

[perrosnk]

Yes:

    subscribe: withFilter(
      () => pubsub.asyncIterator(ON_NEW_ROUND),
      (roundData, args, { userOnDB }) => {
        if (!userOnDB || !userOnDB.complete) {
          return false;
        }
        return _.some(roundData.data, userOnDB.id);
      },
    ),

Although I am not sure about it it might be related to this: graphql/graphql-js#918 (comment)

I am starting the server like this:

new SubscriptionServer({
          schema: executableSchema,
          execute,
          subscribe,
          onConnect,
          // onOperation: (message, params) => {
          //   console.log('onOperation');
          // },
          onDisconnect: (a) => {
            console.log('Disconnecting');
          },
        }, {
          server: ws,
          path: GRAPHQL_PATH,
        });

I am pulling the subscribe from graphql
Where should I call this?

try {
  const result = await subscribe(...);
  if (result.errors) {
    // errors are informative and can be sent to the client
  } else {
    // result is guaranteed to be an AsyncIterable at this point
    return result;
  }
} catch (error) {
  // system error, log the problem and send a failure response to the client.
}

[abernix]

I suspect this problem has been resolved quite some time ago, so I'll close this. If anyone is still experiencing the problem, please feel free to open a new issue with a reproduction using a recent version of Apollo Server. Thanks!