Problem with interface SelectFields and inline fragments

[illambo]

Versions:

• graphql-laravel Version: 5.0.0-rc2
• Laravel Version: 6.18.1
• PHP Version: 7.2.22

Description:

I'm having problems with interface SelectFields and inline fragments.
The query seems does not extract the requested data from interface (see below query with inline fragments), maybe is related to SelectFields.

Steps To Reproduce:

• Setup example

// migrations

Schema::create('humans', function (Blueprint $table) {
      $table->bigIncrements('id');
      $table->string('skin');
      $table->timestamps();
});

Schema::create('droids', function (Blueprint $table) {
      $table->bigIncrements('id');
      $table->string('metal');
      $table->timestamps();
});

// interface

class CharacterInterfaceType extends InterfaceType
{
    protected $attributes = [
        'name' => 'CharacterInterface',
        'description' => 'An example interface',
    ];

    public function fields(): array
    {
        return [
            'id' => [
                'type' => Type::id(),
            ],
        ];
    }

    /**
     * @param $root
     * @return Type
     */
    public function resolveType($root): ?Type
    {
        $type = null;

        if (! is_null($root)) {
            switch (get_class($root)) {
                case \App\Human::class: $type = GraphQL::type('Human'); break;
                case \App\Droid::class: $type = GraphQL::type('Droid'); break;
            }
        }

        return $type;
    }
}

// types

class DroidType extends GraphQLType
{
    protected $attributes = [
        'name' => 'Droid',
        'description' => 'A type',
        'model' => Droid::class,
    ];

    public function fields(): array
    {
        $characterInterface = GraphQL::type('CharacterInterface');
        return array_merge($characterInterface->getFields(), [
            'metal' => [
                'type'          => Type::string(),
                'description'   => 'The metal',
            ],

        ]);
    }

    public function interfaces(): array
    {
        return [
            GraphQL::type('CharacterInterface')
        ];
    }
}

class HumanType extends GraphQLType
{
    protected $attributes = [
        'name' => 'Human',
        'description' => 'A type',
        'model' => Human::class,
    ];

    public function fields(): array
    {
        $characterInterface = GraphQL::type('CharacterInterface');
        return array_merge($characterInterface->getFields(), [
            'skin' => [
                'type'          => Type::string(),
                'description'   => 'The skin',
            ],

        ]);
    }

    public function interfaces(): array
    {
        return [
            GraphQL::type('CharacterInterface')
        ];
    }
}

// query

class CharactersQuery extends Query
{
    protected $attributes = [
        'name' => 'characters',
        'description' => 'A query'
    ];

    public function type(): Type
    {
        return Type::listOf(GraphQL::type('CharacterInterface'));
    }

    public function args(): array
    {
        return [];
    }

    public function resolve($root, $args, $context, ResolveInfo $resolveInfo, Closure $getSelectFields)
    {
        /** @var SelectFields $fields */
        $fields = $getSelectFields();
        $select = $fields->getSelect();
        $relations = $fields->getRelations();

        // this example force to human extractions
        return \App\Human::select($select)->with($relations)->get(); // this  not work ... 
        //return \App\Human::with($relations)->get(); // this  not work ...
        //return \App\Human::get(); // !! this work ...
    }
}

• Seed some human ..
• Run query

query Characters {
  characters {
    __typename
    id
    ...on Droid {
      id
      metal
    }
    ...on Human {
      id
      skin
    }
  }
}

• Check extracted data, human skin is null

[illambo]

Please @mfn can check pull request #607 , maybe can fix the problem.
Thanks