Accept header with multi content-type

Q&A (please complete the following information)

• OS: ubuntu 18.04
• Browser: chrome
• Version: 77.0.3865.90
• Swagger-UI version: 3.23.5
• Swagger/OpenAPI version: Swagger 2.0.9, OpenAPI 3.0 (imported from org.springdoc:springdoc-openapi-ui:1.1.44)

Content & configuration

Swagger/OpenAPI definition:

openapi: 3.0.0
info:
  version: '1.0.0'
  title: 'Test'
paths:
  /test:
    post:
      requestBody:
        content:
          multipart/form-data: # Media type
            schema:            # Request payload
              type: object
              properties:      # Request parts
                file:         #fichier
                  type: string
                  format: binary
                 schema:
                  type: string
      responses:
        '200':
          description: File generated
          content:
            application/xml:
              schema:
                type: string
                format: binary
        '406':
          description: Bad file
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
components:
  schemas:
    Error:
      type: object
      properties:
        message:
          type: array
          items:
            type: string
          description: liste des messages d'erreur
        status:
          type: string
          description: status

Swagger-UI configuration options: i use default index.html file

Describe the bug you're encountering

With Swagger UI, when i made a request (with Try it out), only the content-type from the 200 Response (xml) is used to Accept Header, so when my request produce a 406 Response (json), I have a 500 Response because my backend can't match the content type json with the Accept headers (which has only content type "xml")

I think that the request has to have in the Accept Header all the content type from all the responses (or give a possibility to choose the Accept header)

Thank you ;)

Start by reproducing the Try it out request with the provided OpenAPI definition and inspect how Swagger UI builds the Accept header from the response content types. Done means the request can negotiate both the XML and JSON responses, or provides a documented way to choose the Accept value; the payload names no source files or tests.