OpenAPI 3.1.0 support: [Bug] Wrong field in 'Example value' when using oneOf

[bartgut]

Q&A (please complete the following information)

• OS: macOS
• Browser: safari
• Version: 22
• Method of installation: via Tapir in Scala/using https://editor-next.swagger.io
• Swagger-UI version: 5.4.2 - https://mvnrepository.com/artifact/com.softwaremill.sttp.tapir/tapir-swagger-ui_2.13/1.7.3
• Swagger/OpenAPI version: OpenAPI 3.1.0

Content & configuration

Example Swagger/OpenAPI definition:

openapi: 3.1.0
info:
  title: test
  version: '1.0'
paths:
  /test/route:
    get:
      operationId: getTestRoute
      responses:
        '200':
          description: ''
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/Entity'
components:
  schemas:
    Entity:
      oneOf:
      - $ref: '#/components/schemas/EntityChild1'
      - $ref: '#/components/schemas/EntityChild2'
      discriminator:
        propertyName: $type
        mapping:
          EntityChild1: '#/components/schemas/EntityChild1'
          EntityChild2: '#/components/schemas/EntityChild2'
    EntityChild1:
      required:
      - a
      - b
      - c
      - $type
      type: object
      properties:
        a:
          type: string
        b:
          type: string
        c:
          type: string
        $type:
          type: string
    EntityChild2:
      required:
      - a
      - b
      - d
      - $type
      type: object
      properties:
        a:
          type: string
        b:
          type: string
        d:
          type: string
        $type:
          type: string

Swagger-UI configuration options:

Using https://editor-next.swagger.io

Describe the bug you're encountering

Parameter "c" is added to the EntityChild2 in "Example value" although this field is not in this entity.

To reproduce...

Steps to reproduce the behavior:

1. Go to https://editor-next.swagger.io
2. Paste the above mentioned YAML file

Expected behavior

Example response value for the /test/route endpoint should be:

  {
    "a": "string",
    "b": "string",
    "c": "string",
    "$type": "EntityChild1"
  },
  {
    "a": "string",
    "b": "string",
    "$type": "EntityChild2",
    "d": "string"
  }
]

instead

  {
    "a": "string",
    "b": "string",
    "c": "string",
    "$type": "EntityChild1"
  },
  {
    "a": "string",
    "b": "string",
    "c": "string",
    "$type": "EntityChild2",
    "d": "string"
  }
]

"c" parameter does not belong to EntityChild2 so it should not be there.

Additional context or thoughts

Happens in Scala using Tapir as well. When switching back to OpenAPI 3.0.3 everything seems to be fine

[InterStella0]

This happened for anyOf as well.

[char0n]

Addressed in #9853