Name of service is changed to Service =)

service_client.rb

module ServiceClient
  class ArgumentError < ::ArgumentError; end
  class ServiceClientError < StandardError; end
  class ServiceServerError < ServiceClientError; end

  class Base
    require 'httparty'

    BASE_URL = Rails.application.secrets.service['url']
    HEADERS = {
        'Content-Type' => 'application/json'
    }

    cattr_reader :client_id
    @@client_id = ENV['SERVICE_CLIENT_ID']

    cattr_reader :client_secret
    @@client_secret = ENV['SERVICE_CLIENT_SECRET']

    attr_reader :access_token

    def initialize(access_token = nil)
      @access_token = access_token
    end

    def request(type, url, options = {})
      result = send(type, url, options)
      raise ServiceServerError, 'Service is down' if result.code >= 500
      raise ServiceServerError, 'Service, page is not found' if result.code == 404

      Result.new(result)
    end

    private

    def post(url, options = {})
      HTTParty.post("#{BASE_URL}/#{url}", headers: with_access_token(HEADERS), body: options.to_json)
    end

    def get(url, options = {})
      HTTParty.get("#{BASE_URL}/#{url}", query: options.merge(access_token: access_token))
    end

    def patch(url, options = {})
      HTTParty.patch("#{BASE_URL}/#{url}", body: options.to_json, headers: with_access_token(HEADERS))
    end

    def delete(url, options = {})
      HTTParty.delete("#{BASE_URL}/#{url}", body: options.to_json, headers: with_access_token(HEADERS))
    end

    def require_access_token!
      raise ServiceClient::ArgumentError, 'access_token should be present' if access_token.blank?
    end

    def with_access_token(headers)
      if access_token.present?
        headers.merge('Authorization' => "Bearer #{access_token}")
      else
        headers
      end
    end
  end
end