Subscription types incompatible with graphql-subscription's PubSub

The latest version of graphql-code-generator has changed the subscribe function return type to AsyncIterable<TResult> | Promise<AsyncIterable<TResult>>;

However, when using apollo’s graphql-subscriptions lib, the type returned from their pubsub-engine is AsyncIterator https://github.com/apollographql/graphql-subscriptions/blob/master/src/pubsub-engine.ts#L8

AsyncIterable and AsyncIterator types are incompatible.

Example (this code will throw a type error):

const pubsub = new PubSub();

const typeDefs = gql`
  type Subscription {
    root: String
  }
`

const resolvers: Resolvers = {
  Subscription: {
    root: {
      subscribe: () => {
        // Type 'AsyncIterator<unknown, any, undefined>' is not assignable to type 'AsyncIterable<any> | Promise<AsyncIterable<any>>'.
        return pubsub.asyncIterator('root');
      }
    }
  }
};

What’s the recommended workaround for this issue?

[Urigo]

@mpokrovsky I think graphql-subscriptions 3.0 might be happening soon and I think it includes the changes from @n1ru4l

Could you check if using the current state of their PR solves this issue? https://github.com/apollographql/graphql-subscriptions/pull/250

[Mad-Kat]

In the meantime you could use something like this:

subscribe: () => ({
        [Symbol.asyncIterator]: () => pubsub.asyncIterator<{ numberIncremented: number }>('NUMBER_INCREMENTED'),
      }),