https://github.com/sarkistlt/mongoose-schema-to-graphql

mongoose-schema-to-graphql-example.js

/**
 * MONGOSE SCHEMA
 * [questions-schema.js]
 */
import mongoose from 'mongoose';

const selectSchema = {
  value: String,
  label: String
};

const answerSchema = mongoose.Schema({
  createdAt: mongoose.Schema.Types.Date,
  updatedAt: mongoose.Schema.Types.Date,
  answerId: String,
  title: String,
  displayOrder: Number,
  answersImage: String,
  selectText: String,
  notSelectText: String,
  positiveTip: String,
  negativeTip: String,
  recommended: [selectSchema],
  exclude: [selectSchema],
  isPublished: Boolean
});

export const questionSchema = mongoose.Schema({
  mongooseId: mongoose.Schema.Types.ObjectId,
  simpleId: String,
  question: String,
  defRecommended: [selectSchema],
  createdAt: mongoose.Schema.Types.Date,
  updatedAt: mongoose.Schema.Types.Date,
  isPublished: Boolean,
  multipleChoice: Boolean,
  noneOfThese: Boolean,
  answers: [answerSchema]
});

export const Questions = mongoose.model('questions', questionSchema);


////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 * GRAPHQL TYPE
 * [questions-type.js]
 */
import {GraphQLString} from 'graphql';
import MTGQL from 'mongoose-schema-to-graphql';
import { questionSchema } from './questions-schema';

let queryConfig = {
  name: 'questionType',
  description: 'Question schema',
  class: 'GraphQLObjectType',
  schema: questionSchema,
  exclude: ['mongooseId']
};
let mutationConfig = {
  name: 'questionMutationType',
  description: 'Question Mutation schema',
  class: 'GraphQLObjectType',
  schema: questionSchema,
  exclude: ['mongooseId'],
  props: {
    defRecommended: {type: GraphQLString},
    answers: {type: GraphQLString}
  }
};

export const questionType = MTGQL(queryConfig);

////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 * GRAPHQL QUERY OBJECT
 * [schema-queries.js]
 */
import { questionType } from './questions-type';
import { Questions } from './questions-schema';

let queries = new GraphQLObjectType({
  name: 'Query',
  fields: () => ({
    getQuestions: {
      type: new GraphQLList(questionType),
      args: {
        _id: {
          type: GraphQLString
        },
        simpleId: {
          type: GraphQLString
        },
        isPublished: {
          type: GraphQLBoolean
        },
        answerId: {
          type: GraphQLString
        }
      },
      resolve: (_, args) => Questions.find(args)
    },
  })
});

export default queries;

////////////////////////////////////////////////////////////////////////////////////////////////////
/**
 * GRAPHQL SCHEMA
 * [schema.js]
 */
import { GraphQLSchema } from 'graphql/type';
import queries from './schema-queries';
import mutations from './schema-mutations';

const schema = new GraphQLSchema({
  query,
  mutation,
});

export default schema;