Custom query is not called on Union type using relation field type.

[edgarsn]

Versions:

• graphql-laravel Version: 7.2.0
• Laravel Version: 8.42.1
• PHP Version: 8.0.5

Description:

Custom query in relation field is not being triggered while using Union type.

Steps To Reproduce:

1. Union query

<?php

namespace App\GraphQL\Queries\Guide;

use App\Models\Channel;
use App\Models\LiveStream;
use Closure;
use GraphQL\Type\Definition\ResolveInfo;
use GraphQL\Type\Definition\Type;
use Illuminate\Support\Str;
use Rebing\GraphQL\Support\Facades\GraphQL;
use Rebing\GraphQL\Support\Query;

class LiveItemQuery extends Query
{
    /** @var array Query Attributes */
    protected $attributes = [
        'name' => 'LiveItem',
    ];

    /**
     * Result of query.
     */
    public function type(): Type
    {
        return GraphQL::type('LiveItemUnion');
    }

    /**
     * Arguments to filter query.
     *
     * @return array
     */
    public function args(): array
    {
        return [
            'id' => [
                'type' => Type::nonNull(Type::string()),
            ],
        ];
    }

    /**
     * Query data.
     *
     * @param mixed $root
     * @param array $args
     * @param mixed $context
     * @param ResolveInfo $info
     * @param Closure $getSelectFields
     * @return Channel|LiveStream|null
     */
    public function resolve($root, $args, $context, ResolveInfo $info, Closure $getSelectFields)
    {
        if (Str::startsWith($args['id'], 'channel:')) {
            return Channel::find((int)Str::after($args['id'], 'channel:'));
        } else {
            return Livestream::find((int)$args['id']);
        }
    }
}

2. Union Type

<?php

declare(strict_types=1);

namespace App\GraphQL\Types\Guide;

use App\Models\Model;
use App\Models\Channel;
use App\Models\LiveStream;
use GraphQL;
use Rebing\GraphQL\Support\UnionType;

class LiveItemUnionType extends UnionType
{
    /**
     * @var string[]
     */
    protected $attributes = [
        'name' => 'LiveItemUnion',
    ];

    public function types(): array
    {
        return [
            GraphQL::type('LiveItem'),
            GraphQL::type('Channel'),
        ];
    }

    public function resolveType(Model $value): ?GraphQL\Type\Definition\Type
    {
        if ($value instanceof LiveStream) {
            return GraphQL::type('LiveItem');
        } elseif ($value instanceof Channel) {
            return GraphQL::type('Channel');
        } else {
            return null;
        }
    }
}

3. Model type (Where problem appers)

<?php

namespace App\GraphQL\Types\Guide;

use App\\Models\Channel;
use Carbon\Carbon;
use GraphQL\Type\Definition\Type;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Support\Arr;
use Rebing\GraphQL\Support\Type as GraphQLType;

class ChannelType extends GraphQLType
{
    /** @var array Type attributes */
    protected $attributes = [
        'name' => 'Channel',
        'model' => Channel::class,
    ];

    /**
     * Field definition of type.
     *
     * @return array
     */
    public function fields(): array
    {
        return [
            'id' => [
                'type' => Type::nonNull(Type::int()),
            ],
            'guideItems' => [
                'type' => Type::listOf(\GraphQL::type('GuideItem')),
                'query' => function (array $args, $query, $ctx) {
			// this is never being called through UnionType!
                },
            ],
        ];
    }
}

My client query:

query {
    liveItem(id: "channel:1") {
        ... on LiveItem {
             id
        }
       ... on Channel {
             id
             guideItems {
                 title
             }
        }
    }
}

I Hope it helps. I don't know, if this is only related to version 7 or it's reproducible in version 8 as well.

[mfn]

Seems SelectFields related.

To you want to attempt a PR to fix this?

If not, I would also only accepts tests showing the problem.

[edgarsn]

I'm on vacation in an hour, so no PR from me for now.

But here are tests - edgarsn@471a949

test_customQueryDoesntWorkWhenQueryUsingUnionType - failing example. It should return only 1 comment to post, but returns 2.
test_customQueryWorksWhenQueryTypeIsNotUnionType - this example shows custom query is working when query is returning simply PostType

[mfn]

@edgarsn can you make a PR with the tests?

[edgarsn]

I don't think I'm capable of making fix for this. I can only make a draft PR with tests showing the bug, but it wouldn't help you a lot I guess.

From my observations SelectFields receives a list of all requested union fields without ability to detect on which Type that field belongs to since in UnionType there can be many types defined with the same field name.

For example,

query ($id: String!) {
  searchQuery(id: $id) {
    ... on Post {
        id
        title
        comments {
            id
        }
    }
    ... on Comment {
        id
        title
        body
    }
  }
}

SelectFields constructor $fieldsAndArguments would return:

array:4 [ // /app/src/Support/SelectFields.php:52
  "id" => array:3 [
    "type" => GraphQL\Type\Definition\NonNull^ {#3664
      ...
    }
    "fields" => []
    "args" => []
  ]
  "body" => array:3 [
    "type" => GraphQL\Type\Definition\StringType^ {#3305
      ...
    }
    "fields" => []
    "args" => []
  ]
  "title" => array:3 [
    "type" => GraphQL\Type\Definition\NonNull^ {#3665
      ...
    }
    "fields" => []
    "args" => []
  ]
  "comments" => array:3 [
    "type" => GraphQL\Type\Definition\NonNull^ {#3662
		...
    }
    "fields" => array:1 [
		...
    ]
    "args" => []
  ]
]

And here I'm confused how this could be solved. ID and Title is requested in two different fragments, but here they appear only once in this case.

I hope you understood the problem I'm saying and dealing with in my mind.

[mfn]

I can only make a draft PR with tests showing the bug, but it wouldn't help you a lot I guess.

Au contraire! It would still be helpful! If you could contribute the tests showing the problem, that's already useful on its own!

[edgarsn]

I can only make a draft PR with tests showing the bug, but it wouldn't help you a lot I guess.

Au contraire! It would still be helpful! If you could contribute the tests showing the problem, that's already useful on its own!

Thank you! Will do on monday.