Array of union types does not generate anyOf field

[DjordyKoert]

Example

Given a DTO with an union typed array property:

class ExampleDTO
{
    /**
     * @param (int|string)[] $exampleList
     */
    public function __construct(
        private array $exampleList
    ) {
    }

    /**
     * @return (int|string)[]
     */
    public function getExampleList(): array
    {
        return $this->exampleList;
    }
}

Result in Nelmio generating the following OpenApi schema for the DTO:

"ExampleDTO": {
    "properties": {
        "exampleList": {
            "type": "array",
            "items": {
                "type": "integer"
            }
        }
    },
    "type": "object"
},

Expected result

"ExampleDTO": {
    "properties": {
        "exampleList": {
            "type": "array",
            "items": {
                "anyOf": [
                    {
                        "type": "integer"
                    },
                    {
                        "type": "string"
                    }
                ]
            }
        }
    },
    "type": "object"
},

This can be fixed manually by describing the exampleList property like so:

use OpenApi\Attributes as OA;

class ExampleDTO
{
    /**
     * @param (int|string)[] $exampleList
     */
    public function __construct(
        #[OA\Property(
            type: 'array',
            items: new OA\Items(
                anyOf: [
                    new OA\Schema(type: 'integer'),
                    new OA\Schema(type: 'string'),
            ])
        )]
        private array $exampleList
    ) {
    }

    /**
     * @return (int|string)[]
     */
    public function getExampleList(): array
    {
        return $this->exampleList;
    }
}

Ideally NelmioApiDocBundle should generate a correct schema instead of having to manually define it.

[DerManoMann]

Sounds more like a feature request for the underlying swagger-php library.

There is a long outstanding issue to improve type handling that should cover this.
zircote/swagger-php#1310

[DjordyKoert]

Ah thanks for answering.