Replace Array with Object.

replace-array-with-object/lib/after.rb

@@ -0,0 +1,22 @@
+class Cart
+  attr_reader :products
+
+  def initialize products
+    @products = products.map { |product| Product.new *product }
+  end
+
+  def total
+    products.inject(0) { |sum, product| sum + product.price }
+  end
+
+end
+
+class Product
+  attr_reader :name, :color, :price
+
+  def initialize name, color, price
+    @name  = name
+    @color = color
+    @price = price
+  end
+end

replace-array-with-object/lib/before.rb

@@ -0,0 +1,14 @@
+class Cart
+  attr_reader :products
+
+  def initialize products
+    @products = products
+  end
+
+  def total
+    products.inject(0) { |sum, product|
+      sum + product[2]
+    }
+  end
+
+end

replace-array-with-object/test/test.rb

@@ -3,3 +3,13 @@
 
 require 'before' if ENV["BEFORE"]
 require 'after' unless ENV["BEFORE"]
+
+describe Cart do
+  it "has a list of items" do
+    Cart.new([
+      [ "Sweater"   , "Pink" , 5.0  ],
+      [ "Trousers"  , "Blue" , 8.0  ],
+      [ "Golf Club" , "Gray" , 12.0 ]
+    ]).total.must_equal 25.0
+  end
+end