JAVASCRIPT

Subscription field must return Async Iterable. Received: undefined.

type Subscription {
  postAdded: Post
}

Subscription field must return Async Iterable. Received: undefined.

type Subscription {
  post: PostSubscription
}

type PostSubscription {
  postAdded: Post
}

Subscription field must return Async Iterable. Received: undefined.

Subscription: {
  post: () => ({
    PostSubscription: {}
  })
},
PostSubscription: {
  postAdded: {
    subscribe: () => pubSub.asyncIterator(['postAdded'])
  }
}

Subscription field must return Async Iterable. Received: undefined.

"apollo-server-express": "1.3.6",
"apollo-server-module-graphiql": "1.3.4",
"graphql-subscriptions": "0.5.8",
"graphql": "0.13.2",