Question

启动服务器时出现此错误

错误：预期未定义为GraphQL类型。

更新：我认为这与javascript需要彼此有关。解决这个问题的最佳方法是什么？

我在文件accountTypes.js中有一个帐户类型

const { channelType } = require('../channel/channelTypes');

//Define Order type
const accountType = new GraphQLObjectType({
  name: 'Account',
  description: 'An account',
  fields: () => ({
    id: {
      type: new GraphQLNonNull(GraphQLInt),
      description: 'The id of the account.'
    },
    name: {
      type: new GraphQLNonNull(GraphQLString),
      description: 'Name of the account.'
    },
    channel: {
      type: channelType,
      resolve: resolver(db.Account.Channel),
      description: 'Channel'
    },
    etc...

我的频道类型是在channelTypes.js

中

const { accountType } = require('../account/accountTypes');

// Define Channel type
const channelType = new GraphQLObjectType({
  name: 'Channel',
  description: 'A Channel',
  fields: () => ({
    id: {
      type: new GraphQLNonNull(GraphQLInt),
      description: 'ID of the channel.'
    },
    name: {
      type: new GraphQLNonNull(GraphQLString),
      description: 'Name of the channel',
      deprecationReason: 'We split up the name into two'
    },
    accounts: {
      type: new GraphQLList(accountType),
      description: 'accounts associated with this channel',
      resolve: resolver(db.Channel.Account)
    }
  })
});

有问题的代码在我的channelTypes.js文件中。由于某种原因，accountType因未定义而过来。我使用module.exports导出相应文件中的accountType和channelType。当我在通道文件中注释掉accountType代码时，该帐户工作正常。我正在尝试从帐户或与渠道相关联的所有帐户中获取渠道，但目前只有来自帐户端的渠道才有效。

Answer 1

我回答了一个非常相似的问题here，但我认为它们有点不同。我尝试在那里解释一下模块系统，但基本上答案是在处理递归类型时只需将函数中某个类型的fields属性包装起来。

编辑：也不要对模块对象进行解构。当您具有循环依赖关系时，循环相关模块将获得对模块的引用，但不会进行初始化。然后，当您对它们进行解构时，变量将获得undefined，因为模块还没有属性。

const accountTypes = require('../account/accountTypes');

// Define Channel type
const channelType = new GraphQLObjectType({
  name: 'Channel',
  description: 'A Channel',
  fields: () => ({
    id: {
      type: new GraphQLNonNull(GraphQLInt),
      description: 'ID of the channel.'
    },
    name: {
      type: new GraphQLNonNull(GraphQLString),
      description: 'Name of the channel',
      deprecationReason: 'We split up the name into two'
    },
    accounts: {
      type: new GraphQLList(accountTypes.accountType),
      description: 'accounts associated with this channel',
      resolve: resolver(db.Channel.Account)
    }
  })
});

相关的Graphql对象给出undefined

1 个答案: