Ruby basics review code

ruby-review.rb

# Stores can sell things
class Store
  def sell
    'You bought the thing!'
  end
end

# contains methods common to hot drinks
module HotDrink
  # this defines an instance method make_hot_drink
  # it is available to instances of any class that includes HotDrink
  # it sets the drink, and returns the INSTANCE that it was called on
  def make_hot_drink
    self.drink = 'Hot water'
    self
  end

  def add_cream
    self.drink = ' + cream'
    self
  end
end

# A class of stores that doesn't sell hot drinks
class PetStore < Store
end

# A class of stores that sells coffee
class CoffeeShop < Store
  include HotDrink
  # creates a instance variable @drink and makes it readable and writable
  attr_accessor :drink

  def make_hot_drink
    # drink -  drink is an instance variable
    # We can access drink (read and write to it) because of the
    # attr_accessor :drink above
    # super will look for a method called make_hot_drink in the
    # inheritance chain
    self.drink = drink ' + filter coffee'
    self
  end
end

# A class of stores that sells Tea
# Initialized with one instance variable, name
class TeaShop < Store
  include HotDrink
  attr_reader :type_of_drink
  attr_accessor :drink

  # this method is run when I write TeaShop.new("Rachel's Tea Shop")
  def initialize(name)
    # This sets and instance variable based on the name I passed in
    @name = name
    # This sets an instance variable, @type_of_drink
    # It is automatically set by the inialiaze method and cannot be changed
    @type_of_drink = 'Tea'
  end

  # this method is chainable because it returns self
  def change_name(new_name)
    self.name = new_name.upcase
    self
  end

  # this method is not chanable because it doesn't return self
  def add_awesomeness
    @name + 'Awesome'
  end

  # CLASS method
  # Class methods start with self.
  # Class methods are not available to instances of the class
  # The way to call the class method is TeaShop.tell_me_about_tea_shops
  def self.tell_me_about_tea_shops
    puts 'Tea shops are amazing'
    # self is the class, TeaShop
    self
  end

  # Another class method
  # This method returns a string, not the class, so it is not chainable
  def self.quickly
    "It's a short class method name"
  end

  # This is not a class method because it does NOT begin with self.
  # it is an instance method
  # this method is chainable because it returns self
  def make_hot_drink
    # super looks for a method called make_hot_drink and
    # finds it on the HotDrink module, and executes it
    # the hot drinks module sets the drink instance variable
    # to 'hot water'
    super
    # we can assign to drink because of the attr_accessor above
    # I used += instead of self.drink = self.drink + ' + tea'
    # because the linter told me to
    # this line adds ' + tea' to the drink that we created with
    # calling super
    self.drink += ' + tea'
    self
  end
end

# NAMESPACE EXAMPLE
module SomeNamespace
  class Animal
  end
end

animal = SomeNamespace::Animal.new