find_or_build_blob

# File activestorage/lib/active_storage/attached/changes/create_one.rb, line 52
      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