Not able to decode multipart response

Q&A (please complete the following information)

• OS: Windows
• Browser: Chrome
• Version: 73.
• Method of installation: npm
• Swagger-UI version: Latest
• Swagger/OpenAPI version: OpenAPI 3.0

Content & configuration

Fails to decode the response when it is of multipart type.

Example Swagger/OpenAPI definition:

# your YAML here
  /xyz:
    post:
      parameters:
        - in: query
          name: q
          required: true
          schema:
            type: string
      requestBody:
        required: true
        content:
          multipart/form-data:
            schema:
              type: object
              properties:
                upfile:
                  type: string
                  format: binary
                params:
                  type: string
      responses:
        '200':
          description: OK
          content:
            multipart/form-data:
              schema:
                type: object
                properties:
                  points:
                    type: string
                  file:
                    type: string
                    format: binary
              encoding:
                points:
                  contentType: text/plain
                file:
                  contentType: application/octet-stream

Describe the bug you're encountering

When the UI receives the response from the server where the response has multipart body, the UI doesn't decode the message and displays the result accordingly.

Currently it shows the following error and tries to display everything as text (even the binary junk characters) and the multipart data is not split into corresponding part files.

Response body
Unrecognized response type; displaying content as text.

--29c81d996c8947829f47f91a3c36aa4f
Content-Disposition: form-data; name="points"

[1,2,3,4,5]
--29c81d996c8947829f47f91a3c36aa4f
Content-Disposition: form-data; name="file"; filename="tmp1e95kj4w.nii.gz"
Content-Type: application/octet-stream

��8�\�tmp1e95kj4w.nii��$��V��0?�  7������~��08u���JI))�ʔV�8���T�[Kս�̙�����G����Ͽ����������w�������������?����5����o�5�x������/O���_���?��ϟ���?}

Expected behavior

1. binary data part as downloadable link
2. text/plain data part on UI screen

Start by reproducing the OpenAPI 3.0 example in Swagger UI and inspect the response handling for multipart/form-data. Use the shown multipart response, including its text/plain and binary parts, as the test case; done means text is rendered in the UI and binary data is exposed as a downloadable link without displaying binary junk.