[Swift4] Can't get a model with an array of base class working

Description

A model property typed as an array of polymorphic models stores the base class struct.

My yaml defines these three models:

• section_base (with section_type as a discriminator)
• images_section (with allOf referencing section_base)
• texts_section (with allOf referencing section_base)

In addition, I have a model named doc that includes an array of section_base.

Getting a response from the server, the parsing works, but only for the base model (section_base struct) and not for the other section types.

Is it supported? Am I doing something wrong?

Swagger-codegen version

2.4.0-SNAPSHOT

Swagger declaration file content or url

...

  section_base:
    type: object
    discriminator: section_type
    required:
      - section_type
    properties:
      uid:
        type: string
      section_type:
        type: string
      title:
        type: string
  images_section:
    allOf:
      - $ref: '#/definitions/section_base'
      - type: object
        properties:
          desc:
            type: string
  texts_section:
    allOf:
      - $ref: '#/definitions/section_base'
      - type: object
        properties:
          prefix:
            type: string

...

Command line used for generation

-l swift4

Related issues/PRs

#6941

Start by reproducing the issue with the supplied YAML and the swift4 generator command. Inspect the generated models for section_base, images_section, texts_section, and doc, then verify whether an array of the base type preserves discriminator-based subtypes and add coverage for the expected behavior.