使用 GraphQL 设置订阅的问题

Question

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."
  }
]

Answer 1

字段定义是一个包含以下属性的对象： type 、 args 、 description 、 deprecationReason和resolve 。 除了type之外，所有这些属性都是可选的。 字段映射中的每个字段都必须是这样的对象——您不能像正在做的那样将字段设置为类型。

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,
    },
  })
});

检查文档以获取其他示例。