test

a.rb

class ImportParticipant
  def initialize(source:, :target)
    @source = source
    @target = target
  end

  attr_reader :source, :target

  def call
    data = @source.read_and_parse
    @target.bulk_create(data)
  end
end

# Implement a Source class
class XlsSource
  def initialize(file_reader)
    @file_reader = file_reader
  end

  attr_reader :file_reader

  def read_and_parse
    data = file_reader.read
    parse(data)
  end

  def parse(data)
  end
end

class XlsReader
  def initialize(file)
    @file = file
  end

  def read
    # call Roo
  end
end

class CreateParticipant
  def bulk_create(data)
  end
end

 def call
    data = @source.read_and_parse
    @target.bulk_create(data) if valid?(data)
 end

def valid?(data)
  validators.each { |validator| validator.validate?(data) }
end