在客户端上使用apollo-link,在服务器上使用apollo-server-express的PubSub。在与GraphQL API进行的摩卡测试中得到奇怪的结果:
摩卡咖啡:
import { execute, makePromise } from 'apollo-link';
const uri = 'http://localhost:3001/graphql';
const link = new HttpLink({ uri, fetch });
const subscribe = (query, handlers) => {
const operation = {
query: gql`${query}`,
};
return execute(link, operation).subscribe(handlers);
};
const handlers = {
next: (data) => {
console.log(`received data: ${Date.now()}, ${JSON.stringify(data, null, 2)}`);
},
error: error => console.log(`received error ${error}`),
complete: () => console.log('complete'),
};
it('subscribe', async () => {
const query = `subscription {
info
}`;
subscribe(query, handlers);
});
服务器:
try {
console.log('subscription =>| ', Date.now(), '|', line);
worker.pubsub.publish('infoTopic', { info: line });
} catch (e) {
console.error(e);
}
这是我从测试中看到的内容:
收到的数据:1545013826838,{“错误”:[ { “ message”:“无法为不可为空的字段Subscription.info返回null。”,...
(来自服务器):
订阅=> | 1545013826887 |信息深度1选择深度1 ...
订户收到826 838 , 但发布商的发送时间是826 887
到底是什么?
答案 0 :(得分:1)
我刚遇到这个错误。我找到了一个解决方案,因为我需要发布的对象的字段名称与预订的字段名称匹配。为了说明这一点,请注意架构中的字段名称newPost
与解析程序中的名称匹配,以及正发布到通道和订阅操作的对象的字段名称:
// schema
type Subscription {
newPost: Post!
}
// subscription resolver
newPost: {
subscribe(parent, args, { pubsub }, info)
return pubsub.asyncIterator('new post')
}
}
// in the event publisher
pubsub.publish('new post', { newPost: post })
// the subscription operation
subscription {
newPost {
id
title
body
published
}
}