Compatibility with Down::ChunkedIO (https://github.com/janko/down)

[raivil]

Hi, I'm working with the Shrine gem and uploading PDF files to S3 (direct upload). During the upload, the code is adding some metadata such as the page count.

I noticed that PDF::Reader accepts IO objects as input, but it's not working with the Down::ChunkedIOclass.

This is the code from the shrine uploader:

add_metadata do |file, metadata:, record:, **|
    case metadata["mime_type"]
    when "application/pdf"
      io = file.to_io if file.respond_to?(:to_io)
      reader = PDF::Reader.new(io)

      { page_count: reader.page_count }

Exception:

ArgumentError: input must be an IO-like object or a filename (Down::ChunkedIO)

Code from PDF::Reader that will try to read the IO object. https://github.com/yob/pdf-reader/blob/625e8dca295d8b6a48f634cba812f14fd3b805a4/lib/pdf/reader/object_hash.rb#L601

Is it possible to PDF::Reader to support Down::ChunkedIO?

Any thoughts?

Thank you.