Sample project to highlight an issue processing multipart-form uploads using zio-http

Sample project using scala 3 (3.4.2), zio 2 (2.1.1), zio-http (3.0.0-RC7) and other ancillary ZIO libraries that highlights a problem processing multipart-form data in streaming mode.

Collecting more fields

I am not sure we are using the best option to collect the different fields from the StreamingForm value. The solution we have identified kind of works, even if it feels pretty clanky. Any suggestion on how to do this differently is very welcome.

Processing ZStream data

Depending on how we process the incoming request though, we are getting different results.

/path

If we do consume the full streaming data right away from the ZStream[FormField], we get all the data correctly; this option is implemented in the /path handler. Unfortunately, this means we need to write all the data to a temporary file, and later re-read all the data to actually process its content.

/data

Another option is we keep the ZStream around until we have collected all the needed information, and later process it altogether. This option is implemented in the /data handler; it works file with "small" file uploads (up to ~7KB in size), but hangs with bigger uploads.

What are we doing wrong?

Any suggestion is very welcome