vsavkin

def "length of Spock's and his friends' names"() {
  expect:
  name.size() == length

  where:
  name     | length
  "Spock"  | 5
  "Kirk"   | 4
  "Scotty" | 6
}

vsavkin

def "length of Spock's and his friends' names"() {
  assert "Spock".size() == 5
  assert "Kirk".size() == 3
  assert "Scotty".size() == 6
}

vsavkin

class Person
  validates_presence_of :name
  has_many :addresses
end

vsavkin

class Person < Struct.new(:name, :age)
  def to_s
    "#{name} is #{age} years old"
  end
end

vsavkin

# Framework
# ===========================================
module ContextAccessor
  def context
    Thread.current[:context]
  end
end

module Context
  include ContextAccessor

vsavkin

# Framework
# ===========================================
module ContextAccessor
  def context
    Thread.current[:context]
  end
end

module Context
  include ContextAccessor

vsavkin

class Account
  def decrease_balance(amount); end
  def increase_balance(amount); end
  def balance; end
  def update_log(message, amount); end
  
  def self.find(id); end
end

vsavkin

class TransferringMoney
  include Context

  def self.transfer source_account_id, destination_account_id, amount
    source = Account.find(source_account_id)
    destination = Account.find(destination_account_id)
    TransferringMoney.new(source, destination).transfer amount
  end

  attr_reader :source_account, :destination_account

vsavkin

class TransferringMoney
  include Context
  ...
  
  def transfer amount
    ...
  end

  module SourceAccount
    include ContextAccssor

vsavkin

class TransferringMoney
  include Context

  def self.transfer source_account_id, destination_account_id, amount
    source = Account.find(source_account_id)
    destination = Account.find(destination_account_id)
    TransferringMoney.new(source, destination).transfer amount
  end

  attr_reader :source_account, :destination_account