content type of string/binary property should be octet-stream

Q&A (please complete the following information)

• OS: Ubuntu
• Browser: Firefox 96.0.2
• Method of installation: docker container
• Swagger-UI version: 4.4.1
• Swagger/OpenAPI version: [OpenAPI 3.0]

Content & configuration

Example Swagger/OpenAPI definition:

put:
  requestBody:
    content:
      multipart/form-data:
        schema:
          type: object
          properties:
            myProperty:
              type: string
              format: binary

Describe the bug you're encountering

When sending the above request in swagger UI myProperty is getting the header Content-Type: text/plain but according to this
it should be application/octet-stream.

If the property is a type: string with format: binary or format: base64 (aka a file object), the default Content-Type is application/octet-stream

Expected behavior

The content type for a string/binary property is application/octet-stream.

Start in Swagger UI by reproducing the multipart/form-data request from the issue, using a requestBody property with type string and format binary. Trace how the myProperty part receives its header and verify that the completed behavior uses application/octet-stream instead of text/plain.