Getting error while trying to extend unified schema

[Shreyasnie]

Discussed in #4044

^{Originally posted by Shreyasnie June 16, 2022}
We have two source following are the graphql schema.

OperationResponse

type OperationsResponses {
  AuditLastUpdate: datetime2!
  Description: String
  EndTime: datetime2
  Id: Int!
  LastUpdateDateTimeUtc: datetime2!
  OperationsType: Int!
  PublicationDateTimeUtc: datetime2!
  ResponseState: String
}

Production

type Production {
  id: ID!
  operation_request_id: String!
  operation_response_id: String!
  shift(filter: ShiftFilter, order: ShiftOrder, first: Int, offset: Int): [Shift]
}

type Shift {
  id: ID!
  operation_time: DateTime
  operation_time_duration: Int
  planned_downtime: DateTime
  planned_downtime_duration: Int
  unplanned_downtime: DateTime
  unplanned_downtime_duration: Int
  produce(filter: ProductionFilter): Production
}

type query {
getProduction(operation_response_id: String): Production
}

when i try to extend the operation response schema with production information i;e the relationship is Production.operation_response_id and OperationsResponses.Id

following the configuration in meshrc.yml

additionalTypeDefs: |
  extend type  OperationsResponses {
    Production: Production
  }
additionalResolvers:
  - './resolvers'

following the resolver.ts

import { Resolvers } from './.mesh'

const resolvers: Resolvers = {
  OperationsResponses: {
    Production: {
      selectionSet: /* GraphQL */`
      {
        operation_response_id
      }
      `,
      resolve: async (root, _args, context, info) => {
        return await  context['Shift Model Flexible Model'].Query.getProduction({
          root,
          args: {
            operation_response_id : root.Id.toString()
          },
          context,
          info,
        })
      }
    }
  },
  }

export default resolvers

I am able to see production inside operation response in graphql mesh gateway playground but when i query get below error from graphql tools

 GraphQLError: not a valid GraphQL query
    at C:\Source\Repos\graphql.wtf-graphql-mesh-as-a-gateway-main\node_modules\@graphql-tools\batch-execute\index.js:318:39
    at Array.forEach (<anonymous>)
    at splitResult (C:\Source\Repos\graphql.wtf-graphql-mesh-as-a-gateway-main\node_modules\@graphql-tools\batch-execute\index.js:316:30)
    at C:\Source\Repos\graphql.wtf-graphql-mesh-as-a-gateway-main\node_modules\@graphql-tools\batch-execute\index.js:361:20
    at processTicksAndRejections (node:internal/process/task_queues:96:5)
    at async Promise.all (index 0)
    at async DataLoader.batchExecuteLoadFn [as _batchLoadFn] (C:\Source\Repos\graphql.wtf-graphql-mesh-as-a-gateway-main\node_modules\@graphql-tools\batch-execute\index.js:358:25)

Below is the query i tried to execute

query MyQuery {
  OperationsResponses {
    Production {
      id
      shift {
        planned_downtime
        planned_downtime_duration
      }
    }
  }
}

and response I got is below

{
  "errors": [
    {
      "message": "not a valid GraphQL query",
      "path": [
        "OperationsResponses"
      ]
    }
  ],
  "data": null
}
```</div>