Trouble merging type-graphql schema with existing schema

[tony-oldport]

Based on a previous discussion about migrating to TypeGraphQL incrementally in a large project, I'm trying to migrate only types first while leaving resolvers as they were. I've tried a number of different ways, but the end result is 'Unknown type' errors for all types referenced in the resolvers schema definition. Here's a simplified version of a couple of my attempts:

Notification.ts

@ObjectType()
export class Notification {

  @Field({ nullable: true })
  body?: string

  @Field({ nullable: true })
  id?: string

  @Field({ nullable: true })
  link?: string

  @Field(type => ID, { nullable: true })
  organizationId?: string | number

  @Field(type => ID)
  recipientId: string | number

  @Field({ nullable: true })
  seen?: boolean

  @Field({ nullable: true })
  seenAt?: Date

  @Field({ nullable: true })
  sentAt?: Date

  @Field({ nullable: true })
  subject?: string

  @Field({ nullable: true })
  type?: string
}

typeDefs.ts

import { gql } from 'apollo-server-express'

export const typeDefs = gql`
  type Query {
    getNotifications(userId: ID!): [Notification]!
  }
`

index.ts

import { ApolloServer, ApolloError, makeExecutableSchema, mergeSchemas } from 'apollo-server-express'
import { typeDefs } from './typeDefs'

const resolvers = {
  Query: {
    getNotifications (obj, args, context, info) {
      ... query notifications
      return notifications
    }
  }
}

// Attempt 1
  const generatedSchema = await buildSchema({
    resolvers: [GetServiceResolver]  // was necessary to create at least 1 TypeGraphQL resolver
  })

  const declaredSchema = makeExecutableSchema({ typeDefs, resolvers })
  const schema = mergeSchemas({ schemas: [declaredSchema, generatedSchema] })

  const server = new ApolloServer({
    schema,
   ...

Attempt 2 (using graphql-tools)

import { mergeResolvers, mergeTypeDefs } from '@graphql-tools/merge'
import { makeExecutableSchema } from '@graphql-tools/schema'
import { typeDefs } from './typeDefs'

  const resolvers = {
    Query: {
      getNotifications (obj, args, context, info) {
        ... query notifications
        return notifications
      }
    }
  }

  const { typeDefs: generatedTypeDefs, resolvers: generatedResolvers } = await buildTypeDefsAndResolvers({
    resolvers: [GetServiceResolver, CreateServiceResolver],
    globalMiddlewares: [ResolverAuthorization]
  })
  const mergedTypes = mergeTypeDefs([generatedTypeDefs, typeDefs])
  const mergedResolvers = mergeResolvers([generatedResolvers, resolvers])
  const schema = makeExecutableSchema({ typeDefs: mergedTypes, resolvers: mergedResolvers })
  ...

I've tried a number of other combinations of buildSchema, buildTypeDefsAndResolvers with apollo and graphql-tools versions of makeExecutableSchema and mergeSchemas, but every attempt ends with Error: Unknown type "Notification". I'm not sure it would be helpful to list every attempt here. I'm clearly either missing something pretty obvious or maybe there's a bug of some sort.

[MichalLytek]

You need to manually add the object types classes to schema via the orphanedTypes property.
TypeGraphQL traverse imports chain and include all the types defined in TypeGraphQL's @Resolver's, but since you do not define them, you can't rely on that mechanism 😉

[tony-oldport]

You're a life saver! Thanks, that did the trick.

import { buildTypeDefsAndResolvers } from 'type-graphql'
import { mergeResolvers, mergeTypeDefs } from '@graphql-tools/merge'
import { makeExecutableSchema } from '@graphql-tools/schema'


  const { typeDefs: generatedTypeDefs, resolvers: generatedResolvers } = await buildTypeDefsAndResolvers({
    resolvers: [GetServiceResolver, CreateServiceResolver],
    orphanedTypes: [Notification],
    globalMiddlewares: [ResolverAuthorization]
  })
  const mergedTypes = mergeTypeDefs([generatedTypeDefs, typeDefs])
  const mergedResolvers = mergeResolvers([generatedResolvers, resolvers])
  const schema = makeExecutableSchema({ typeDefs: mergedTypes, resolvers: mergedResolvers })