Come up with a general way to conditionally process transforms based on data type

[eightBitter]

There are times when I need to monkey-patch an existing transform to conditionally check and process an array rather than a string. It would be nice if we could come up with a general way for transforms to do this without having to rewrite every transform.

Currently this is a pretty low priority given that this is a rare use-case - I might have to monkey-patch one transform per ArchivesSpace project.

[eightBitter]

Here's a case where I monkey-patched Clean::StripFields

# frozen_string_literal: true
module Ahc
  module Transforms
    # Transformations to clean up data
    module Clean

      class StripFields
        def initialize(fields:)
          @fields = [fields].flatten
        end

        # @param row [Hash{ Symbol => String }]
        def process(row)
          @fields.each do |field|
            val = row.fetch(field, nil)
            if val.is_a? Array
              row[field] = val.map{|item| item.strip}
            else
              row[field] = if val.nil? || val.empty?
                            nil
                          else
                            val.strip
                          end
                        end
          end
          row
        end
      end
    end
  end
end