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