Fix parent schema discriminator validation

[MaggieKimani1]

Fixes #402

[darrelmiller]

The validation process needs to be recursive. The current check only validates direct children of the schema. The following example still fails.

openapi: 3.0.0
info:
  description: Service to test discriminator
  version: 1.0.0
  title: Test Service
servers:
  - url: 'https://localhost'
paths:
  /test:
    post:
      description: Sample post
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/Parent'
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Parent'
components:
  schemas:
    Parent:
      type: object
      oneOf:
         - $ref: '#/components/schemas/ChildA'
         - $ref: '#/components/schemas/ChildB'
      discriminator:
         propertyName: type
    ChildA:
      allOf:
      - $ref: "#/components/schemas/BaseChild"
      - properties:
          AName:
            type: string
        type: object
    ChildB:
      allOf:
      - $ref: "#/components/schemas/BaseChild"
      - properties:
          BName:
           type: string
        type: object
    BaseChild:
      properties:
        type:
         type: string
      type: object

[darrelmiller]

The checking needs to be made recursive. See the example I included in the overview comments.

[MaggieKimani1]

The checking needs to be made recursive. See the example I included in the overview comments.

Thanks for the correction. Resolving..