为什么“阿波罗客户端”无法通过“带有协议的模拟套接字”接收订阅事件

Question

我正在为我的nodejs apollo graphql项目编写订阅的集成测试。我正在使用mock-socket-with-protocol模拟websocket网络层。

下面是我在jest中的测试代码。当我运行单元测试时，永远不会调用测试用例中的next()部分。测试用例由于超时而失败。我的代码有什么错误吗？

const pubsub = new PubSub();
const resolvers = {
  Subscription: {
    somethingChanged: {
      subscribe: () => {
        return pubsub.asyncIterator('update_event');
      },
    },
  },
};

const typeDefs = gql`
  type Topic {
    topic: String
  }
  type Subscription {
    somethingChanged: Topic
  }
`;

const gqClient = () => {
  const customServer = new Server('ws://localhost:8080');
  const graphqlSchema = makeExecutableSchema({ typeDefs, resolvers });
  SubscriptionServer.create(
    {
      schema: graphqlSchema,
      execute,
      subscribe,
    },
    customServer,
  );

  const wsLink = new WebSocketLink({
    uri: 'ws://localhost:8080',
    webSocketImpl: WebSocket,
  });

  return new ApolloClient({
    link: wsLink,
    cache: new InMemoryCache(),
  });
};

test('test', (done) => {
  gqClient()
    .subscribe({
      query: gql`
        subscription {
          update {
            topic
          }
        }
      `,
    })
    .subscribe({
      next(data) {
        // Notify your application with the new arrived data
        console.log('get update ', data);
        done();
      },
      error(err) {
        console.error(err);
        done();
      },
    });

  setTimeout(() => {
    pubsub.publish('update_event', {
      somethingChanged: { topic: 'hello' },
    });
  }, 1000);
});

我对这些测试的依赖性：

"devDependencies": {
    "@babel/core": "^7.7.4",
    "@babel/plugin-proposal-class-properties": "^7.7.4",
    "@babel/preset-env": "^7.7.4",
    "apollo-cache-inmemory": "^1.6.3",
    "apollo-client": "^2.6.4",
    "apollo-link-ws": "^1.0.19",
    "babel-eslint": "^10.0.3",
    "babel-jest": "^24.9.0",
    "eslint": "^6.7.1",
    "eslint-config-airbnb": "^18.0.1",
    "eslint-config-airbnb-base": "^14.0.0",
    "eslint-plugin-import": "^2.18.2",
    "eslint-plugin-jsx-a11y": "^6.2.3",
    "eslint-plugin-react": "^7.14.3",
    "eslint-plugin-react-hooks": "^1.7.0",
    "husky": "^3.1.0",
    "jest": "^24.9.0",
    "jest-html-reporter": "^2.7.0",
    "mock-socket-with-protocol": "^7.1.1"
  }
"dependencies": {
    "apollo-server-express": "^2.9.12",
    "apollo-server-testing": "^2.9.12",
    "express": "^4.17.1",
    "graphql": "^14.5.8",
    "graphql-subscriptions": "^1.1.0",
    "graphql-tag": "^2.10.1",
    "graphql-tools": "^4.0.6",
    "node-cache": "^5.0.2",
    "retry": "^0.12.0",
    "subscriptions-transport-ws": "^0.9.16",
    "uuid": "^3.3.3",
    "ws": "^7.2.0"
  },