issue542.yml

openapi: "3.0.0"
info:
  version: 1.0.0
  title: Swagger Petstore
  license:
    name: MIT
servers:
  - url: http://petstore.swagger.io/v1
paths: {}
#paths:
#  /pets:
#    patch:
#      requestBody:
#        content:
#          application/json:
#            schema:
#              oneOf:
#                - $ref: '#/components/schemas/Cat'
#                - $ref: '#/components/schemas/Kitten'
#              discriminator:
#                propertyName: pet_type
#      responses:
#        '200':
#          description: Updated
components:
  schemas:
    Cat:
      anyOf:
        - $ref: "#/components/schemas/Kitten"
        - type: object
    #          properties:
    #            hunts:
    #              type: boolean
    #            age:
    #              type: integer
    #            offspring:
    Kitten:
      $ref: "#/components/schemas/Cat" #ko

#      type: string                     #ok

#      allOf:                               #ko
#        - $ref: '#/components/schemas/Cat'