class ActiveStorage::Attached::Changes::CreateOne

def find_or_build_blob
  case attachable
  when ActiveStorage::Blob
    attachable
  when ActionDispatch::Http::UploadedFile, Rack::Test::UploadedFile
    ActiveStorage::Blob.build_after_unfurling(
      io: attachable.open,
      filename: attachable.original_filename,
      content_type: attachable.content_type,
      record: record,
      service_name: attachment_service_name
    )
  when Hash
    ActiveStorage::Blob.build_after_unfurling(
      **attachable.reverse_merge(
        record: record,
        service_name: attachment_service_name
      ).symbolize_keys
    )
  when String
    ActiveStorage::Blob.find_signed!(attachable, record: record)
  else
    raise ArgumentError, "Could not find or build blob: expected attachable, got #{attachable.inspect}"
  end
end