Graphql: Working with child resolvers

[cschroeter]

I'm submitting a...

[ ] Regression 
[x] Bug report
[ ] Feature request
[ ] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead post your question on Stack Overflow.

Current behavior

Given that GraphQL schema

type User {
  name: String
  address: Address
}

type Address {
  street: String
  location: Location
}

type Location {
  latitude: Float!
  longitude: Float!
}

type Query {
  users: [User!]
}

and this UserResolver

import { Resolver, Query, ResolveProperty } from '@nestjs/graphql';

@Resolver('User')
export class UserResolver {
  @Query()
  users() {
    return [{ name: 'Hans' }];
  }

  @ResolveProperty()
  address() {
    return { street: 'Main Street' };
  }

  @Resolver('Address')
  @ResolveProperty('location')
  location() {
    return {
      latitude: 8.3,
      longitude: 1.3,
    };
  }
}

Nest termaintes with (node:85597) UnhandledPromiseRejectionWarning: Error: Address.Address defined in resolvers, but not in schema

Expected behavior

Instead of writing a dedicated ChildResolver I would like to resolve a property within the ParentResolver liek this:

@Resolver("Parent")
export class ParentResolver {
  @Resolver("Child")
  @ResolveProperty("ChildProperty")
  childProperty() {}
}

Minimal reproduction of the problem with instructions

https://github.com/cschroeter/nestjs-graphql-resolver/tree/master/src

What is the motivation / use case for changing the behavior?

Reduce the amount of resolvers needed for simple ChildProperties.

Environment

Nest version: latest


For Tooling issues:
- Node version: latest  
- Platform:  Mac 

Others:

[cschroeter]

Also given that schema

interface Animal {
  name: String!
  friends: [Animal!]!
}

type Cat implements Animal {
  name: String!
  friends: [Animal!]!
}

type Dog implements Animal {
  name: String!
  friends: [Animal!]!
}

type Query {
  animals: [Animal!]!
}

import { Resolver, ResolveProperty, Parent, Query } from '@nestjs/graphql';

@Resolver('Animal')
export class AnimalResolver {
  @Query()
  animals() {
    return [{ name: 'Susi' }];
  }

  @ResolveProperty()
  async friends(@Parent() animal) {
    return [{ name: 'Strolch' }];
  }

  @ResolveProperty()
  __resolveType(animal): string {
    // it is always a cat 😁
    return 'Cat';
  }
}

Fails with "message": "Cannot return null for non-nullable field Cat.friends."
This will fail also :(

[GabrielGil]

So, this was closed, but did you find any solution or got to any conclusion? I am trying to implement with some typings a cursor based pagination under the same schema but got to face the same problem.

type Query {
  categories(): CategoryConnection!
}

type CategoryConnection {
  totalCount: Int!
  edges: [CategoryEdge!]!
}

type CategoryEdge {
  cursor: String!
  node: CategoryType!
}

type CategoryType {
  id: ID!
  name: String!
}

What was the final result to your problem?

[lock[bot]]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.