带有 Keystone 的 GraphQL 需要字段类型必须是输出类型，但得到：未定义答案

【问题标题】：GraphQL with Keystone wants field type must be Output Type but got: undefined带有 Keystone 的 GraphQL 需要字段类型必须是输出类型，但得到：未定义
【发布时间】：2017-09-21 10:40:37
【问题描述】：

我不想为我的 keystone.js 应用程序创建 GraphQL 端点（通过 express 中间件 express-graphql）。

这是我的 Keystone 架构：

const keystone = require('keystone');

const Types = keystone.Field.Types;

const User = new keystone.List('User');

const localStorage = new keystone.Storage({
  adapter: keystone.Storage.Adapters.FS,
  fs: {
    path: './src/upload/avatars',
    publicPath: '/upload/avatars',
  },
});

User.add({
  name: { type: Types.Name, required: true, index: true },
  email: { type: Types.Email, initial: true, index: true },
  password: { type: Types.Password, initial: true, required: true },
}, 'Profile', {
  photo: { type: Types.File, storage: localStorage },
}, 'Permissions', {
  isAdmin: { type: Boolean, label: 'Can access Keystone', index: true },
},
);

// Provide access to Keystone
User.schema.virtual('canAccessKeystone').get(function () {
  return this.isAdmin;
});

User.defaultColumns = 'name, email, isAdmin';
User.register();

keystone.js 中作为文件类型实现的字段 Photo 的关键问题。

在我的 GraphQL 架构下：

import {   GraphQLSchema,   GraphQLID,   GraphQLList,   GraphQLNonNull,   GraphQLObjectType, } from 'graphql';

const keystoneTypes = require('keystone-graphql').Types; const keystone = require('keystone');

const User = keystone.list('User');

const userType = new GraphQLObjectType({   name: 'User',   fields: ()
=> ({
    id: { type: new GraphQLNonNull(GraphQLID) },
    name: { type: new GraphQLNonNull(keystoneTypes.Name(User.fields.name)) },
    email: keystoneTypes.Email(User.fields.email),
    photo: keystoneTypes.File(User.fields.photo),   }), });

const queryRootType = new GraphQLObjectType({   name: 'Query',   fields: {
    users: {
      type: new GraphQLList(userType),
      resolve: () =>
        User.model.find().exec(),
    },
    user: {
      type: userType,
      args: {
        id: {
          description: 'id of the user',
          type: new GraphQLNonNull(GraphQLID),
        },
      },
      resolve: (_, args) => User.model.findById(args.id).exec(),
    },   }, });

export default new GraphQLSchema({   query: queryRootType, });

以及包含在分叉 keystone-graphql 包中的字段文件实现：

'use strict';

const GraphQL = require('graphql');

const KeystoneFileType = new GraphQL.GraphQLObjectType({
    name: 'KeystoneFile',
    fields: {
    size: { type: GraphQL.GraphQLInt },
    mimetype: { type: GraphQL.GraphQLString },
    filename: { type: GraphQL.GraphQLString },
  },
});

module.exports = (field) => KeystoneFileType;

我想用 File 字段向 keystone-graphql 包发出拉取请求，当它可以正常工作时。目前我有来自 GraphQL 的错误：

Error: User.photo field type must be Output Type but got: undefined.
    at invariant (/Users/Vadim/Dropbox/WebStormProjects/mulibwanji/node_modules/graphql/jsutils/invariant.js:19:11)
    at /Users/Vadim/Dropbox/WebStormProjects/mulibwanji/node_modules/graphql/type/definition.js:335:5
    at Array.forEach (native)
    at defineFieldMap (/Users/Vadim/Dropbox/WebStormProjects/mulibwanji/node_modules/graphql/type/definition.js:326:14)
    at GraphQLObjectType.getFields (/Users/Vadim/Dropbox/WebStormProjects/mulibwanji/node_modules/graphql/type/definition.js:284:44)
    at typeMapReducer (/Users/Vadim/Dropbox/WebStormProjects/mulibwanji/node_modules/graphql/type/schema.js:206:25)
    at typeMapReducer (/Users/Vadim/Dropbox/WebStormProjects/mulibwanji/node_modules/graphql/type/schema.js:187:12)
    at /Users/Vadim/Dropbox/WebStormProjects/mulibwanji/node_modules/graphql/type/schema.js:216:20
    at Array.forEach (native)
    at typeMapReducer (/Users/Vadim/Dropbox/WebStormProjects/mulibwanji/node_modules/graphql/type/schema.js:207:27)
    at Array.reduce (native)
    at new GraphQLSchema (/Users/Vadim/Dropbox/WebStormProjects/mulibwanji/node_modules/graphql/type/schema.js:95:34)
    at Object.<anonymous> (/Users/Vadim/Dropbox/WebStormProjects/mulibwanji/graphql/Schema.js:58:16)

【问题讨论】：

标签： express graphql keystonejs

【解决方案1】：

此时我绕过了这个：

export const File = new GraphQLObjectType({
  name: 'KeystoneFileType',
  fields: {
    size: { type: GraphQLInt },
    filename: { type: GraphQLString },
    mimetype: { type: GraphQLString },
  },
});

所以此时它必须没有 (field) => FileType，如我所见，但如果有人能找出真正的问题，我会很高兴。

【讨论】：