abstract_service.rb

# frozen_string_literal: true

# Abstract service class
class AbstractService
  class << self
    def call(*args, &block)
      new(*args, &block).call
    end
  end

  def call
    raise NotImplementedError, 'Dont instantiate AbstractService, please, work with descendants'
  end

  def success?
    @status == :success
  end
end

error

# frozen_string_literal: true

module Api
  module V1
    # graceful API errors handling
    class Error < StandardError
      # class << self
      def self.not_found(record = 'record')
        {
          "status" => 'error',
          "code" => 404,
          "message" => Message.not_found(record),
          "data" => {}
        }
      end

      def self.bad_request(message = '')
        {
          "status" => 'error',
          "code" => 400,
          "message" => Message.bad_request(message),
          "data" => {}
        }
      end

      def self.parameter_missing
        {
          "status" => 'error',
          "code" => 400,
          "message" => Message.parameter_missing,
          "data" => {}
        }
      end

      def self.access_denied
        {
          "status" => 'error',
          "code" => 403,
          "message" =>  Message.access_denied,
          "data"=> {}
        }
      end

      def self.unauthorized
        {
          "status" => 'error',
          "code" => 401,
          "message" => Message.not_authorized,
          "data" => {}
        }
      end
    end
  end
end

message.rb

# frozen_string_literal: true

class Message
  class << self
    def not_found(record = 'record')
      "Sorry, #{record} is not found"
    end

    def not_authorized
      'You are not authorized.'
    end

    def access_denied
      'Access denied'
    end

    def bad_request(parameter = '')
      "Bad request #{parameter}"
    end

    def parameter_missing(parameter = 'parameter')
      "#{parameter} is missing"
    end
  end
end

response.rb

module Response
  def json_response(object, status = :ok)
    render json: object, status: status
  end

  def json(object, status = :ok)
    {
      data: object,
      status: status
    }
  end
end