OAS Core Rule: $ref can have description and summary siblings

[CanVuralStudocu]

Describe the bug
I think according to the OpenAPI spec (https://swagger.io/specification/#reference-object) reference objects can have $ref, summary and description fields. But the Spectral rule no-$ref-siblings marks the description sibling of $ref as error.

To Reproduce

1. Given this OpenAPI/AsyncAPI document

    {
    	"$ref": "#/components/schemas/Pet",
        "description": "This is a sibling description that should be allowed."
    }

2. Run this CLI command spectral lint
3. See error no-$ref-siblings $ref must not be placed next to any other properties

Expected behavior
description and summary should be allowed as a sibling to $ref

[davidkeaveny]

https://swagger.io/docs/specification/using-ref/#sibling suggests otherwise:

Any sibling elements of a $ref are ignored. This is because $ref works by replacing itself and everything on its level with the definition it is pointing at.

Instead, you have to use allOf:

{
  "allOf": [
    { "$ref": "#/components/schemas/Pet" }
  ],
  "description": "This is a sibling description that should be allowed."
}

[CanVuralStudocu]

I found this issue that confirms $ref can have siblings: OAI/OpenAPI-Specification#2744

[mnaumanali94]

@CanVuralStudocu That's an addition to the OAS3.1 spec. This rule as configured doesn't apply to OAS3.1 and is only enabled for OAS3 and 2