requestBody.content.multipart/form-data.schema.properties.<file>.contentEncoding (and contentMediaType) is not valid OS3.0

[NPellet]

Those two fields (contentEncoding and contentMediaType) are not in the OS 3.0 spec, though they are in the OS 3.1 spec.

Our generator only supports 3.0, so it fails there. I will investigate what a fix would take.

[NPellet]

Content encoding is added here https://github.com/danielgtaylor/huma/blob/main/formdata.go#L241

[NPellet]

contentMediaType is added here https://github.com/danielgtaylor/huma/blob/c7a8a7965d84e4aded17671da32bea8c69e4201e/schema.go#L168

[NPellet]

I see there's downgrade code already

https://github.com/danielgtaylor/huma/blob/c7a8a7965d84e4aded17671da32bea8c69e4201e/openapi.go#L1624-L1639

[NPellet]

Here's our schema

      requestBody:
        content:
          multipart/form-data:
            encoding:
              Data:
                contentType: text/plain
              file:
                contentType: text/plain
            schema:
              properties:
                Data:
                  $ref: "#/components/schemas/CertificateImportData"
                file:
                  contentEncoding: binary
                  contentMediaType: application/octet-stream
                  format: binary
                  type: string
              required:
                - file
              type: object

[NPellet]

Ok this is indeed not 3.0.3 valid, and it's under the SchemaObject specification:

https://spec.openapis.org/oas/v3.0.3#schema-object

In general (not just for requestBody or for multipart encoding), those 2 properties are not allowed in OS 3.0.3

[NPellet]

I would propose something like https://github.com/danielgtaylor/huma/pull/919