node.js - 带有子节点的 graphql 订阅似乎对我不起作用

Question

首先，如果我有下一个代码结构，订阅就可以工作

图式

type Subscription {
   somethingChanged: IResult
}
type IResult {
   id: String!
}

解析器

export const resolvers = {
   Query: {
   },
   Mutation: {
   },
   Subscription: {
      somethingChanged: {
         subscribe: () => pubSub.asyncIterator(SOMETHING_CHANGED_TOPIC)
      }
   },
};

当我尝试将somethingChanged节点作为另一个account节点的子节点时，问题就变成了一个问题，如下所示：

所以下一个模式和解析器不起作用

type Subscription {
   account(token: String!): IAccountAction
}
type IResult {
   id: String!
}
type IAccountAction {
   somethingChanged: IResult
}

export const resolvers = {
   Query: {
   },
   Mutation: {
   },
   Subscription: {
      account: (root: any, token: string) => ({
         somethingChanged: {
            subscribe: () => pubSub.asyncIterator(SOMETHING_CHANGED_TOPIC)
         }
      })
   },
};

错误

{ "error": { "message": "订阅字段必须返回 Async Iterable。收到：未定义" } }

我相信这不是问题，只是误解））请帮助我））

---

可能有帮助的附加信息：

服务器.ts

import {resolvers} from './generated/resolvers';
import {typeDefs} from './generated/mergedGQLSchemas';
import http from 'http';

const express = require('express');
const { ApolloServer, gql } = require('apollo-server-express');

const PORT = 4001;

const app = express();

const server = new ApolloServer({
   typeDefs,
   resolvers,
});

server.applyMiddleware({
   app
});

const httpServer = http.createServer(app);
server.installSubscriptionHandlers(httpServer);

httpServer.listen(PORT, () => {
  console.log(` Server ready at http://localhost:${PORT}${server.graphqlPath}`);
  console.log(` Subscriptions ready at ws://localhost:${PORT}${server.subscriptionsPath}`);
});