[Go] Heterogeneous array with oneOf

Created by: langston-barrett

Description

Structs are not properly generated to handle arrays with item schema using oneOf. For instance, for the swagger.yml in the next section, an empty struct is generated:

type Bar struct {
}

This is what should be generated:

type Bar struct {
	Obj1 []string `xml:"Obj1"`
	Obj2 []bool   `xml:"Obj2"`
}

See the following Go playground: https://play.golang.org/p/rdNNL6nUUl1

openapi-generator version

Docker container version

OpenAPI declaration file content or url

---
openapi: 3.0.0
info:
  title: oneof
  version: 0.1.0

paths:
  "/foo":
    get:
      summary: foo
      responses:
        '200':
          description: OK
          content:
            application/xml:
              schema:
                "$ref": "#/components/schemas/Bar"

components:
  schemas:
    Bar:
      type: array
      items:
        oneOf:
        - $ref: '#/components/schemas/Obj1'
        - $ref: '#/components/schemas/Obj2'

    Obj1:
      type: string

    Obj2:
      type: bool

Command line used for generation

sudo docker run --rm -v ${PWD}:/local \
     openapitools/openapi-generator-cli generate \
     -i /local/swagger.yml \
     -g go \
     -o /local/generated/ \       
     -D withXml=true | grep -v INFO

Steps to reproduce

Related issues/PRs

#15

Suggest a fix/enhancement

The Go codegen should support arrays with oneOf schemata by integrating both/all types as list properties of the generated struct as in the above example.