Support polymorphic response from the nested list level

[dralpus]

We need to support the polymorphic response at the nested list (2nd layer response - from the data model). Clients should handle the different type of objects inside the lists as long as they have discriminator parameters.

We have a DataModel such as:

class PetResponse
{
 public string message {get; set;}
 // <-- We need an annotation support here for overridding the base type (Pet) and instead support discriminator parameter, with oneOf functionality.
 public List<Pet>{get; set;}
}

End result of the swagger document should be look like this: Sample result: https://app.swaggerhub.com/apis/dralpus/test/1.0.0-oas3

openapi: 3.0.1
info:
  title: Polymorphic List Sample
  version: "1.0.0-oas3"
servers:
  - url: 'https://localhost'
paths:
  /feeds:
    get:
      tags:
        - News
      summary: Result array contains any of the specified types
      operationId: getMsnFeeds
      parameters:
        - name: query
          in: query
          description: 'Get '
          schema:
            type: string
      responses:
        '200':
          description: List of compositeCards
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/PetResponse'
components:
  schemas:
    PetResponse:
      type: object
      properties:
        result:
          type: array
          items:
            # Actually PetResponse has an Pet type array to support Polymorphism, but it is overridden by the extended class types
            oneOf:
              - $ref: '#/components/schemas/Cat'
              - $ref: '#/components/schemas/Dog'
              - $ref: '#/components/schemas/Lizard'
          discriminator:
            propertyName: pet_type
        message:
          type: string
    Lizard:
      allOf:
        - $ref: '#/components/schemas/Pet'
        - type: object
          properties:
            lovesRocks:
              type: boolean
    Pet:
      type: object
      properties:
        name:
          type: string
        petType:
          type: string
      required:
        - name
        - petType
    Cat:
      description: A representation of a cat
      allOf:
        - $ref: '#/components/schemas/Pet'
        - type: object
          properties:
            huntingSkill:
              type: string
              description: The measured skill for hunting
              enum:
                - clueless
                - lazy
                - adventurous
                - aggressive
          required:
            - huntingSkill
    Dog:
      description: A representation of a dog
      allOf:
        - $ref: '#/components/schemas/Pet'
        - type: object
          properties:
            packSize:
              type: integer
              format: int32
              description: the size of the pack the dog is from
              default: 0
              minimum: 0
          required:
            - packSize

[Shwetap05]

@dralpus to support this feature we will need to start supporting custom annotations for request/response contracts properties as currently we use only the default <summary> tag to fetch the property description. I will need to think about the design as the work is not going to be trivial to support this.

[MikesGlitch]

Any news on this? Would be really helpful for a project I'm working on.