Medium 702687394e3d-application-service

medium-702687394e3d-application-service.rb

require 'dry/matcher/result_matcher'

module ApplicationService
  module ClassMethods
    def call(params, &block)
      service_outcome = self.new.execute(params)
      if block_given?
        Dry::Matcher::ResultMatcher.call(service_outcome, &block)
      else
        service_outcome
      end
    end
  end

  module InstanceMethods
    include Dry::Monads[:result, :do]

    def execute(params)
      yield validate_params(params)
      super(params)
    end
    
    def validate_params(params)
      if self.class.constants.include? :ValidationSchema
        validation_outcome = self.class.const_get(:ValidationSchema).call(params)
  
        return Failure(validation_outcome.errors.to_h) if validation_outcome.failure?  
      end

      Success(params)
    end
  end

  def self.included(klass)  
    klass.prepend InstanceMethods
    klass.extend ClassMethods
  end
end