Define item, watermelon and pack objects.

Gemfile

@@ -1,6 +1,7 @@
source 'https://rubygems.org'

gem 'bundler'
gem 'money'
gem 'rspec'

group :test do

Gemfile.lock

@@ -5,7 +5,10 @@ GEM
      simplecov
    diff-lcs (1.3)
    docile (1.1.5)
    i18n (0.8.6)
    json (2.1.0)
    money (6.9.0)
      i18n (>= 0.6.4, < 0.9)
    rake (12.0.0)
    rspec (3.6.0)
      rspec-core (~> 3.6.0)
@@ -32,6 +35,7 @@ PLATFORMS
DEPENDENCIES
  bundler
  codeclimate-test-reporter (~> 1.0.0)
  money
  rake
  rspec
  simplecov

lib/item.rb

@@ -0,0 +1,12 @@
require 'money'
require_relative 'pack'
I18n.enforce_available_locales = false

# Item class
class Item
  attr_reader :name

  def initialize(name)
    @name = name
  end
end

lib/pack.rb

@@ -0,0 +1,9 @@
# Pack class
class Pack
  attr_reader :qty, :price

  def initialize(qty, price)
    @qty = qty
    @price = price
  end
end

lib/watermelon.rb

@@ -0,0 +1,28 @@
require_relative 'item'

# Watermelon class
class Watermelon < Item
  attr_reader :pack

  OPTIONS = [3, 5].freeze

  def initialize(name)
    super(name)
    @pack = nil
  end

  def pack_size(selection)
    return unless OPTIONS.include?(selection)

    return @pack = Pack.new(3, Money.new(699, 'NZD')) if selection == 3
    @pack = Pack.new(5, Money.new(899, 'NZD')) if selection == 5
  end
end

# watermelon = Watermelon.new('watermelon')
# puts watermelon

# size = watermelon.pack_size(3)

# puts size.qty
# puts size.price

spec/item_spec.rb

@@ -0,0 +1,14 @@
require 'rspec'
require 'spec_helper'
require './lib/item'

describe Item do
  describe '#initialize' do
    it 'should have a name attribute which is a String' do
      instance = Item.new('Watermelons')

      expect(instance.name).to be_a String
      expect(instance.name).to eq 'Watermelons'
    end
  end
end

spec/pack_spec.rb

@@ -0,0 +1,20 @@
require 'rspec'
require 'spec_helper'
require './lib/pack'

describe Pack do
  describe '#initialize' do
    it 'should have a qty attribute which is an Integer' do
      instance = Pack.new(3, 6.99)

      expect(instance.qty).to be_a Integer
      expect(instance.qty).to eq 3
    end

    it 'should have a price attribute which is an instance of Money' do
      instance = Pack.new(3, Money.new(699, 'NZD'))

      expect(instance.price).to be_a Money
    end
  end
end

spec/watermelon_spec.rb

@@ -0,0 +1,34 @@
require 'rspec'
require 'spec_helper'
require './lib/watermelon'

describe Watermelon do
  describe '#initialize' do
    it 'should have a name attribute which is an String' do
      instance = Watermelon.new('watermelon')

      expect(instance.name).to be_a String
      expect(instance.name).to eq 'watermelon'
    end

    it 'should have a pack attribute which is nil' do
      instance = Watermelon.new('watermelon')

      expect(instance.pack).to be_nil
    end
  end

  describe '#pack_size' do
    it 'should return nil if selection is not present in OPTIONS array' do
      instance = Watermelon.new('watermelon')

      expect(instance.pack_size(1)).to be_nil
    end

    it 'should return an instance of Pack if selection is present in OPTIONS array' do
      instance = Watermelon.new('watermelon')

      expect(instance.pack_size(3)).to be_a Pack
    end
  end
end