openapi3filter: use FileBodyDecoder if the format is specified as binary

[dbarrosop]

This allows uploading arbitrary files treating them as binary by specifying a schema like:

  /files/:
    post:
      requestBody:
        required: true
        content:
          multipart/form-data:
            schema:
              type: object
              properties:
                file[]:
                  type: array
                  items:
                    type: string
                    format: binary <----- this is the important bit
              required:
                - file[]

without having to add openapi3filter.RegisterBodyDecoder("some/thing", openapi3filter.FileBodyDecoder) for every particular type of file that users might be uploading and for which we may have no knowledge of ahead of time when building a service to upload arbitrary files.

I don't think this is currently supported in any other way, I don't think so.

[dbarrosop]

I am a bit confused about the failing tests, go test ./... works without any issues but go test -count=10 ./... fails. Why is that? Do you know?

P.S: Looks like my test is creating some side-effects on the other tests as removing it fixes the problem but running it standalone works fine...

P.S2: It turns out the existing upload zip test was polluting the environment and needed a cleanup

[fenollp]

Thanks! Also, I love nhost :)

[mieltn]

@fenollp @dbarrosop
hi guys, i think there might be an issue here
i have

...
attachment:
    type: string
    format: binary
...

it is a field of multipart form, when the attachment sent has a header of type registered in init, it will try to decode it with registered decoder, while i expect FileBodyDecoder on binary fields

maybe we could do something like

mediaType := parseMediaType(contentType)
if isBinary(schema) {
	value, err := FileBodyDecoder(body, header, schema, encFn)
	return mediaType, value, err
}

decoder, ok := bodyDecoders[mediaType]
if !ok {
	return "", nil, &ParseError{
		Kind:   KindUnsupportedFormat,
		Reason: fmt.Sprintf("%s %q", prefixUnsupportedCT, mediaType),
	}
}