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node.js - 使用 GraphQL 设置订阅问题

问题描述

再会：

我正在尝试为订阅设置我的 graphql 服务器。这是我的 schema.js

const ChatCreatedSubscription = new GraphQLObjectType({ 
  name: "ChatCreated",
  fields: () => ({
    chatCreated: {  
          subscribe: () => pubsub.asyncIterator(CONSTANTS.Websocket.CHANNEL_CONNECT_CUSTOMER) 
    }
  })
});

const ChatConnectedSubscription = {
  chatConnected: {
      subscribe: withFilter(
         (_, args) => pubsub.asyncIterator(`${args.id}`),
         (payload, variables) => payload.chatConnect.id === variables.id,
      )
  }
}




const subscriptionType = new GraphQLObjectType({
  name: "Subscription",
  fields: () => ({
    chatCreated: ChatCreatedSubscription,
    chatConnected: ChatConnectedSubscription
  })
});

const schema = new GraphQLSchema({
  subscription: subscriptionType
});

但是，当我尝试运行订阅服务器时出现此错误：

ERROR introspecting schema:  [
  {
    "message": "The type of Subscription.chatCreated must be Output Type but got: undefined."
  },
  {
    "message": "The type of Subscription.chatConnected must be Output Type but got: undefined."
  }
]

标签： node.jsgraphqlgraphql-jsgraphql-subscriptions

解决方案

字段定义是包含以下属性的对象：type、args、description和。所有这些属性都是可选的，除了. 字段映射中的每个字段都必须是这样的对象——您不能只是将字段设置为您正在做的类型。deprecationReasonresolvetype

不正确：

const subscriptionType = new GraphQLObjectType({
  name: "Subscription",
  fields: () => ({
    chatCreated: ChatCreatedSubscription,
    chatConnected: ChatConnectedSubscription
  })
});

正确的：

const subscriptionType = new GraphQLObjectType({
  name: "Subscription",
  fields: () => ({
    chatCreated: {
      type: ChatCreatedSubscription,
    },
    chatConnected: {
      type: ChatConnectedSubscription,
    },
  })
});

检查文档以获取更多示例。

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