How to use the graphql-compose.TypeComposer.create function in graphql-compose

{ id: 1, firstName: "Tom", lastName: "Coleman" },
    { id: 2, firstName: "Sashko", lastName: "Stubailo" },
    { id: 3, firstName: "Mikhail", lastName: "Novikov" },
]

const posts = [
    { id: 1, authorId: 1, title: "Introduction to GraphQL", votes: 2 },
    { id: 2, authorId: 2, title: "Welcome to Apollo", votes: 3 },
    { id: 3, authorId: 2, title: "Advanced GraphQL", votes: 1 },
    { id: 4, authorId: 3, title: "Launchpad is Cool", votes: 7 },
]

// -----------------------------------------------------------------------------
// #2. Creating Types

const AuthorTC = TypeComposer.create({
    name: "Author",
    fields: {
        id: "Int!",
        firstName: "String",
        lastName: "String",
    },
})

const PostTC = TypeComposer.create({
    name: "Post",
    fields: {
        id: "Int!",
        title: "String",
        votes: "Int",
        authorId: "Int",
    },

{ id: 4, authorId: 3, title: "Launchpad is Cool", votes: 7 },
]

// -----------------------------------------------------------------------------
// #2. Creating Types

const AuthorTC = TypeComposer.create({
    name: "Author",
    fields: {
        id: "Int!",
        firstName: "String",
        lastName: "String",
    },
})

const PostTC = TypeComposer.create({
    name: "Post",
    fields: {
        id: "Int!",
        title: "String",
        votes: "Int",
        authorId: "Int",
    },
})

// -----------------------------------------------------------------------------
// #3. Create relations between Types

PostTC.addFields({
    author: {
        // you may provide type name as string 'Author',
        // but for better developer experience use Type instance `AuthorTC`

const { PlantTC, GardenTC, MuseumTC, HerbariumTC, PlantSearchResultItemType } = modelsTC
  const CategoryEnum = new GraphQLEnumType({
    name: 'CategoryEnum',
    values: require('../../category')
  })

  const AutoCompleteResultItem = new GraphQLObjectType({
    name: 'ScientificNameItem',
    fields: {
      scientificName: { type: GraphQLString },
      familyName: { type: GraphQLString },
      name: { type: GraphQLString },
      _id: { type: GraphQLString }
    }
  })
  const AutoCompleteResultItemTC = TypeComposer.create(AutoCompleteResultItem)
  AutoCompleteResultItemTC.extendField('scientificName', {
    resolve: source => (scientificSplit(source.scientificName))
  })

  const PlantSearchResolver = new Resolver({
    name: 'search',
    type: new GraphQLObjectType({
      name: 'PlantSearchResult',
      fields: {
        result: { type: new GraphQLList(PlantSearchResultItemType) },
        count: { type: 'Int' }
      }
    }),
    args: {
      text: { type: '[String]', defaultValue: [] },
      categories: { type: new GraphQLList(CategoryEnum), defaultValue: ['garden', 'herbarium', 'museum'] },

exports.convertToSourceTC = async (opts = {}) => {
    const tc = TypeComposer.create({
        name: `${opts.prefix || ""}${opts.graphqlTypeName}${opts.postfix || ""}`,
    })

    const fieldsMap = await retrieveTableFields(opts.mysqlClient, opts.mysqlTable)

    const fields = {}
    Object.keys(fieldsMap).forEach(field => {
        const fieldName = fieldsMap[field].Field

        fields[fieldName] = mysqlTypeToGraphQLType(fieldsMap[field].Type)
    })
    console.log(tc)
    
    tc.addFields(fields)

    return tc

module.exports = () => {
  const { TypeComposer } = require('graphql-compose')
  const { GraphQLList } = require('graphql')

  const ErrorTC = TypeComposer.create(`
    type Error {
      code: Int,
      message: String!,
    }
  `)

  const ErrorResolver = require('../resolvers/ErrorResolver')
  
  ErrorTC.addResolver({
    name: 'error',
    kind: 'query',
    type: new GraphQLList(ErrorTC.getType()),
    resolve: ErrorResolver.resolver
  })

  return { ErrorTC }

const _ = require('lodash')
const mongoose = require('mongoose')
const { TypeComposer } = require('graphql-compose')
const { GraphQLList } = require('graphql')

const FileType = TypeComposer.create('File')
FileType.addFields({
  url: { type: 'String' }
})
exports.AddTypeToImageField = (TC) => {
  TC.removeField('images')
  TC.addFields({
    images: {
      type: new GraphQLList(FileType.getType()),
      resolve: source => source.images
    },
    thumbnailImage: {
      projection: { images: 1 },
      type: 'String',
      resolve: (source) => {
        if (source.images.length === 0) {
          return '/static/images/placeholder150x150.png'