Brief Description

I have a simple file attachment uploader that stores files in GCS storage. On my model before_save callback I store the size of the image file in my database by accessing:

class Comment
   before_save :store_file_size
   include CommentUploader::Attachment(:file)

   def store_file_size
      file.size
   end
end

Expected behavior

The tempfile plugin should not affect normal behavior that works fine when the tempfile plugin is not used.

Actual behavior

When I add the tempfile plugin, I get a Shrine::Error - uploaded file must be opened.
Calling file.open prior to file.size or file.dimensions works. The tempfile plugin is forcing a requirement to call file.open

System configuration

Ruby version: 2.5.0

Shrine version: 3.3.0

Thanks for an amazing gem and for your consideration of this issue.