s3_headers proc/lambda doesn't work

[zainzafar]

Describe the bug

To Reproduce
Steps to reproduce the behavior:

has_attached_file :asset,
  s3_headers: lambda { |attachment|
    puts "*********** attachment = #{attachment.to_json}"
    {
      'Cache-Control' => "max-age=#{1.year.to_i}",
      'Expires' => 1.year.from_now.httpdate,
      'Content-Disposition': "Attachment; file=#{attachment.asset_file_name}"
    }
  }

Expected behavior
When uploading a PDF file named "Test.pdf", it should print out

*********** attachment = {...., asset_file_name: "Test.pdf", asset_content_type: "application/pdf".... }

Desktop (please complete the following information):

• OS: Docker ruby 2.6.6

Additional context
s3_headers doesn't get called with attachment therefore attachment.asset_file_name returns nil

[ssinghi]

Hi @zainzafar Thanks for the bug report.
If you can please submit a PR to fix this with a failing test case, that will be really great

[sasharevzin]

Just to save some time searching, here is the commit when proc support was added