GraphQL\Tests\Executor\AbstractTest::testResolveTypeOnInterfaceYieldsUsefulError PHP Method

    function testResolveTypeOnInterfaceYieldsUsefulError()
    {
        $DogType = null;
        $CatType = null;
        $HumanType = null;
        $PetType = new InterfaceType(['name' => 'Pet', 'resolveType' => function ($obj) use(&$DogType, &$CatType, &$HumanType) {
            if ($obj instanceof Dog) {
                return $DogType;
            }
            if ($obj instanceof Cat) {
                return $CatType;
            }
            if ($obj instanceof Human) {
                return $HumanType;
            }
            return null;
        }, 'fields' => ['name' => ['type' => Type::string()]]]);
        $HumanType = new ObjectType(['name' => 'Human', 'fields' => ['name' => ['type' => Type::string()]]]);
        $DogType = new ObjectType(['name' => 'Dog', 'interfaces' => [$PetType], 'fields' => ['name' => ['type' => Type::string()], 'woofs' => ['type' => Type::boolean()]]]);
        $CatType = new ObjectType(['name' => 'Cat', 'interfaces' => [$PetType], 'fields' => ['name' => ['type' => Type::string()], 'meows' => ['type' => Type::boolean()]]]);
        $schema = new Schema(['query' => new ObjectType(['name' => 'Query', 'fields' => ['pets' => ['type' => Type::listOf($PetType), 'resolve' => function () {
            return [new Dog('Odie', true), new Cat('Garfield', false), new Human('Jon')];
        }]]]), 'types' => [$DogType, $CatType]]);
        $query = '{
          pets {
            name
            ... on Dog {
              woofs
            }
            ... on Cat {
              meows
            }
          }
        }';
        $expected = ['data' => ['pets' => [['name' => 'Odie', 'woofs' => true], ['name' => 'Garfield', 'meows' => false], null]], 'errors' => [['message' => 'Runtime Object type "Human" is not a possible type for "Pet".', 'locations' => [['line' => 2, 'column' => 11]], 'path' => ['pets', 2]]]];
        $actual = GraphQL::execute($schema, $query);
        $this->assertEquals($expected, $actual);
    }