apneadiving

def accept_invitation
  Wf.new
    .chain(user: :user) { AcceptInvitation.new(invitation).call }
    .chain {|outflow| render json: { user: outflow.user } }
    .on_dam do |error_pool|
      render json: { errors: error_pool.full_messages }, status: 422
    end
end

apneadiving

# User model 
class User < ActiveRecord::Base
  has_many :invitations
end
# Invitation Model
class Invitation < ActiveRecord::Base
  belongs_to :inviter, class_name: 'User'
  def accept
    self.accepted = true
  end

apneadiving

class AcceptInvitation
  include Waterfall
  include ActiveModel::Validations

  CENTS_PAID_FOR_AFFILIATION = 100

  validate :ensure_invitation_not_accepted
  
  def initialize(invitation)
    @invitation = invitation

apneadiving

class CreateUserFromInvitation
  include Waterfall
  
  def initialize(invitation)
    @invitation = invitation
  end
  
  def call
    chain { build_user }
    when_falsy { user.save }

apneadiving

class CreditUser
  include Waterfall
  
  def initialize(user:, cents:)
    @user, @cents = user, cents
  end
  
  def call
   # credit logic goes here and dams on error
  end

apneadiving

# test utility for the script
def assert(actual, expected)
  if actual == expected
    puts "ok #{expected}"
  else
    puts "ko, you expected: #{expected} but got #{actual}"
  end
end

# first implementation, more functional programming friendly, pure method

apneadiving

class ParamsSlicer
  def initialize(params, *whitelist)
    @params = params
    @nested_whitelist = whitelist.extract_options!
    @whitelist = whitelist
  end

  def call
    params.slice(*whitelist).tap do |result|
      nested_whitelist.each do |k, v|

apneadiving

range1 = ::Scheduling::DateRange.new(1.day.ago..Time.now)
range2 = ::Scheduling::DateRange.new(2.days.ago..Time.now)

range1.exclusion(range2) => []
range2.exclusion(range1) => [::Scheduling::DateRange.new(2.days.ago..1.day.ago)]

apneadiving

# frozen_string_literal: true
source "https://rubygems.org"

git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }

gem 'twilio-ruby'
gem 'dotenv'
gem 'waterfall'

apneadiving

class ApplyProductStateOrder
  def initialize(status_change_order)
    @status_change_order = status_change_order
  end

  def call
    ActiveRecord::Base.transaction do
      state_change = update_product

      status_change_order.update_timestamps(state_change)