Little domain service thing

domain_service.rb

require "concord"
require "procto"

class DomainService < Module
  def initialize(*attrs, call: :call)
    @attrs = attrs
    @call = call
  end

  def included(descendant)
    descendant.send(:include, Procto.call(@call))
    descendant.send(:include, Concord::Public.new(*@attrs))
    
    # Define Failure error on module/class
    descendant.const_set "Failure", failure_error_class
  end

  # General Failure from service, defined as a subclass of StandardError.
  # An object can be passed in so the rescue block can inspect and use
  # error data. For instance with AR Model errors.
  def failure_error_class
    Class.new(StandardError) do
      include Concord::Public.new(:object)
    end
  end
end

my_service.rb

# Create a service to handle creating an ActiveRecord::Model
class MyService
  include DomainService.new(:attributes)
  
  def call
    model = MyModel.create(params)
    
    if model.errors.present?
      fail Failure.new(model), "Could not create model."
    end
  end
  
  # Could use strong_params too
  def params
    attributes.require(:csv)
  end
end