Allowed value not showing for oneOf nested in allOf

[hugovanversendaal]

When oneOf is nested within allOf, the allowed value of the schema within oneOf is not showing. The title and the description of the nested schemas are fine, just not the allowed value. When a constant value is used within the upper allOf, the allowed value is showing properly

Context

I am using nested schemas in my project, but the allowed values are not visible. The users now have to look directly into openapi.yaml to find the allowed values.

Current Behavior

Allowed values are not shown in Elements when they are part of a schema within oneOf that is nested in allOf.

See the contents of the OAS below:

openapi.yaml

openapi: 3.1.0
info:
  title: Sample API
  version: 0.1.9

paths:
  /pets:
    get:
      requestBody:
        content:
          application/json:
            schema:
              oneOf:
                - $ref: "#/components/schemas/Cat"
                - $ref: "#/components/schemas/Dog"
              discriminator:
                propertyName: pet_type

components:
  schemas:
    Pet:
      type: object
      required:
        - pet_type
      properties:
        pet_type:
          type: string
      discriminator:
        propertyName: pet_type
    Dog: # "Dog" is a value for the pet_type property (the discriminator value)
      allOf: # Combines the main `Pet` schema with `Dog`-specific properties
        - $ref: "#/components/schemas/Pet"
        - type: object
          # all other properties specific to a `Dog`
          properties:
            bark:
              type: boolean
            foo:
              type: string
              const: bar
            breed:
              type: string
              # enum: [Dingo, Husky, Retriever, Shepherd]
              oneOf:
                - $ref: "#/components/schemas/Dingo"
                - $ref: "#/components/schemas/Husky"
                - $ref: "#/components/schemas/Retriever"
                - $ref: "#/components/schemas/Shepherd"

    Cat: # "Cat" is a value for the pet_type property (the discriminator value)
      allOf: # Combines the main `Pet` schema with `Cat`-specific properties
        - $ref: "#/components/schemas/Pet"
        - type: object
          # all other properties specific to a `Cat`
          properties:
            hunts:
              type: boolean
            age:
              type: integer

    Dingo:
      title: Dingo
      type: string
      const: Dingo
      description: The dingo is an ancient (basal) lineage of dog found in Australia.
    Husky:
      title: Husky
      type: string
      const: Husky
      description: Husky is a general term for a dog used in the polar regions, primarily and specifically for work as sled dogs.
    Retriever:
      title: Retriever
      type: string
      const: Retriever
      description: A retriever is a type of gun dog that retrieves game for a hunter.
    Shepherd:
      title: Shepherd
      type: string
      const: Shepherd
      description: The German Shepherd, also known in Britain as an Alsatian, is a German breed of working dog of medium to large size.

Expected Behavior

Allowed values are visible in Elements when they are part of a schema within oneOf that is nested in allOf.

Possible Workaround/Solution

Because description is displayed properly, I use description with code markup to simulate the allowed values field. However, this is not the preferred use of the description field.

Steps to Reproduce

1. Download and unzip attachment: elements-bug-oneof.zip.
2. run docker compose up.
3. go to http://localhost:8080/elements.html.
4. compare openapi.yaml from the html-folder with the Dog-schema in browser.

Environment

• Version used: 8.3.4
• Environment name and version (e.g. Chrome 39, node.js 5.4): Firefox 129.0
• Operating System and version (desktop or mobile): desktop, nginx 1.27.0