Code Explainers

Code explainers tagged #service object

ruby 
class WeeklySignupsReport
  DEFAULT_WEEKS = 12
 
  def initialize(weeks: DEFAULT_WEEKS, source: User.all)

Building a weekly signups report in Rails

service object aggregation group by
Intermediate 7 steps
ruby 
class MailingListDeduplicator
  GMAIL_DOMAINS = %w[gmail.com googlemail.com].freeze
 
  def initialize(subscribers)

Deduplicating a mailing list by canonical email

deduplication normalization service object
Intermediate 8 steps
ruby 
class CartMergeService
  def initialize(guest_cart:, user_cart:)
    @guest_cart = guest_cart
    @user_cart = user_cart

Merging a guest cart into a user cart in Rails

service object transactions idempotency
Intermediate 7 steps
ruby 
class FundsTransfer
  class InsufficientFundsError < StandardError; end
 
  def initialize(source:, destination:, amount:)

Atomic money transfers with Rails transactions

service object database transactions row locking
Advanced 9 steps
ruby 
class CheckoutService
  Result = Struct.new(:success?, :order, :error, keyword_init: true)
 
  def self.call(...)

How a Rails checkout service object works

service object transactions result object
Intermediate 9 steps