Apolloサブスクリプションリゾルバーは決してアクティブにならない？

Question

私のコンポーネントはサブスクリプションクエリを呼び出していますが、なんらかの理由でサブスクリプションリゾルバにアクセスしていません。ブレークポイントはアクティブ化されません。しかし、クライアントでは、GraphQLサブスクリプションエラーが発生します：

"Subscription must return Async Iterable. Received: undefined"

何が原因である可能性がありますか？

事前にすべての情報に感謝します。

購読QUERY

const IM_SUBSCRIPTION_QUERY = gql` 
     subscription getIMsViaSubscription($fromID: String!, $toID: String!){ 
      IMAdded(fromID:$fromID, toID: $toID){ 
      id, 
      fromID, 
      toID, 
      msgText, 
      myUserData{ 
       id, 
       name_first, 
       name_last, 
       picture_large, 
       picture_medium, 
       picture_thumbnail 
       my_category 
      } 
      } 
     } 
`; 

RESOLVER

Subscription: { 
    IMAdded(IMThatWasAdded) { 
     debugger; <== IS NEVER ACTIVATED 
     subscribe: withFilter(() => SubscriptionServer.pubsub.asyncIterator(IM_ADDED_CHANNEL), (newIM, args) => { 
      const callIsFromMsgFoldersComponent = args.toID == 0; 
      var result; 
      if (callIsFromMsgFoldersComponent){ 
       result = (newIM.fromID === args.fromID || newIM.toID === args.fromID); 
      } else { 
       result = ((newIM.fromID === args.fromID && newIM.toID === args.toID) || (newIM.fromID === args.toID && newIM.toID === args.fromID)); 
      } 
      return result; 
     }) 

COMPONENT

const withDataAndSubscription = graphql(GETIMS_QUERY, { 
    options({toID}) { 
     console.log(GETIMS_QUERY); 
     const fromID = Meteor.userId(); 
     return { 
      fetchPolicy: 'cache-and-network', 
      variables: {fromID: `${fromID}`, toID: `${toID}`} 
     }; 
    } 
    , 
    props: props => { 
     debugger; 
     return { 
      loading: props.data.loading, 
      instant_message: props.data.instant_message, 
      subscribeToMore: props.data.subscribeToMore, 
      subscribeToNewIMs: params => { 
       debugger; <==IS ACTIVATED AS EXPECTED 
       console.log(IM_SUBSCRIPTION_QUERY); <==IS OKAY 
       const fromID = Meteor.userId(); 
       const toID = params.toID; 
       return props.data.subscribeToMore({ 
        document: IM_SUBSCRIPTION_QUERY, 
        variables: {fromID: `${fromID}`, toID: `${toID}`}, 
        updateQuery: (previousResult, {subscriptionData}) => { 
         if (!subscriptionData.data) { 
          return previousResult; 
         } 
         const newMsg = subscriptionData.data.createIM; 
         return update(previousResult, { 
          instant_message: { 
           $push: [newMsg], 
          }, 
         }); 
        } 
       }); 
      } 
     }; 
    }, 
}) 
; 

Answer 1

サーバー-SID eセットアップ、突然変異/サブスクリプションのリゾルバは、昨年末からApolloライブラリをベースにした私のポストのコードからかなり変更されました。ここでは、現在アポロLIBSで動作するコードはthis tutorialを経由して、次のとおりです。

Serverのセットアップ

import express from 'express'; 
import { graphqlExpress, graphiqlExpress } from 'graphql-server-express'; 
import bodyParser from 'body-parser'; 
import cors from 'cors'; 
import { execute, subscribe } from 'graphql'; 
import { createServer } from 'http'; 
import { SubscriptionServer } from 'subscriptions-transport-ws'; 

import schema from '/imports/api/schema'; 

//SET UP APOLLO QUERY/MUTATIONS/PUBSUB 
const METEOR_PORT = 3000; 
const GRAPHQL_PORT = 4000; 
const server = express(); 

server.use('*', cors({ origin: 'http://localhost:${METEOR_PORT}' })); 

server.use('/graphql', bodyParser.json(), graphqlExpress({ 
    schema 
})); 

server.use('/graphiql', graphiqlExpress({ 
    endpointURL: '/graphql', 
    subscriptionsEndpoint: `ws://localhost:${GRAPHQL_PORT}/subscriptions` 
})); 

// Wrap the Express server 
const ws = createServer(server); 
ws.listen(GRAPHQL_PORT,() => { 
    console.log(`GraphQL Server is now running on http://localhost:${GRAPHQL_PORT}`); 
    // Set up the WebSocket for handling GraphQL subscriptions 
    new SubscriptionServer({ 
     execute, 
     subscribe, 
     schema 
    }, { 
     server: ws, 
     path: '/subscriptions', 
    }); 
}); 
//END OF SET UP APOLLO PUBSUB 

MUTATION RESOLVER

Mutation: { 
     createIM(root, args, context) { 
      var associatedUsers = []; 
      associatedUsers.push(args.fromID); 
      associatedUsers.push(args.toID); 
      var IDofNewIM; 

      return Promise.resolve() 
       .then(() => { 
        const newIM = connectors.IMs.create(args); 
        return newIM; 
       }) 
       .then(IMAdded => { 
        // publish subscription notification 
        pubsub.publish(IM_ADDED_CHANNEL, { IMAdded, args}); 
        return IMAdded; 
       }) 
       .catch((err)=> { 
        console.log(err); 
       }); 
     }, 

購読RESOLVER

IMAdded: { 
    subscribe: withFilter(
     () => pubsub.asyncIterator(IM_ADDED_CHANNEL), 
     (IMAdded, args) => { 
      IMAdded = IMAdded.IMAdded; 
      var result = ((IMAdded.fromID === args.fromID && IMAdded.toID === args.toID) || (IMAdded.fromID === args.toID && IMAdded.toID === args.fromID)); 
      return result; 
     } 
    ) 
},