Fix pubsub.asyncIterator typescript type

[xialvjun]

package: graphql-subscriptions
version: 1.1.0

expected behavior: code like down is typescript ok

Subscription: {
  on_new_count: {
    subscribe: async function*(_, args, ctx, info) {
      const iter = pubsub.asyncIterator<number>('on_new_count');
      // this line errors
      for await (const iterator of iter) {
      }
    },
    resolve: (_: number) => _,
  },
};

actual behavior: typescript errors Type 'AsyncIterator<number, any, undefined>' must have a '[Symbol.asyncIterator]()' method that returns an async iterator.

[xialvjun]

I know I can use withFilter, but then type generated by graphql-codegen will be lost , ex - args should can be its real type, but using withFilter, I got any

[saeidfiy]

i solve it with subscribe: async (
_: void,
{ Inputs: { chatId } }: { Inputs: SendMessageSubVariable }
): Promise<AsyncIterator<unknown, { message: string }, undefined>> => {
const key = messageKey(chatId);
return pubsub.asyncIterator([key]);
}
}

[Miljoen]

Hi guys I came across this issue and this worked for me:

    Subscription: {
        userUpdated: {
            subscribe: () => ({
                [Symbol.asyncIterator]: () => pubSub.asyncIterator(['USER_UPDATED']),
            }),
        },
    },

Basically the best way to handle this is to make your Iterator an Iterable

Issue came up as part of strongly typing my Apollo Server Resolvers using Codegen

[glasser]

Looks like this is more relevant to the (not super actively maintained, unfortunately) graphql-subscriptions project rather than apollo-server so I will close this issue. Looks like some related discussion on apollographql/graphql-subscriptions#143 and apollographql/graphql-subscriptions#192

Actually I think this might be fixed by apollographql/graphql-subscriptions#232 which @hwillson has scheduled to be released in 3.0 apollographql/graphql-subscriptions#250