Bulk discount for Pico2

README.md

@@ -18,7 +18,3 @@ Run tests with `ruby -Ilib:test tests.rb`
 * Cart can be stored in an array of strings
 * Cart items should be validated against a known list of products
 * We need a hash of products and their prices
-
-## Open Questions
-
-* How do we apply discounts?

checkout.rb

@@ -34,8 +34,10 @@ class Checkout
     # BOGOF ZERO2W
     discount = (@items.count(:ZERO2W) / 2.0).floor * AVAILABLE_ITEMS[:ZERO2W]
 
-
-    # TODO: Bulk PICO2
+    # Bulk PICO2
+    if(items.count(:PICO2) >= 3)
+      discount += items.count(:PICO2) * 0.50
+    end
 
     return discount
   end

tests.rb

@@ -21,7 +21,7 @@ class TestCheckout < Minitest::Test
     assert_equal [:PI5, :ZERO2W, :PICO2].sort, @checkout.items.sort
   end
 
-  def test_that_total_is_the_sum_of_all_items # Not accounting for discounts at the moment
+  def test_that_total_is_the_sum_of_all_items_when_no_discounts_apply
     @checkout.add(:PI5)     # 60.00
     @checkout.add(:ZERO2W)  # 15.00
     @checkout.add(:PICO2)   #  4.00
@@ -39,7 +39,7 @@ class TestCheckout < Minitest::Test
 
   def test_that_bogof_applied
     4.times do
-      @checkout.add(:ZERO2W)
+      @checkout.add(:ZERO2W) # Should remove 2 Zeros
     end
 
     assert_equal 30.00, @checkout.total
@@ -47,9 +47,45 @@ class TestCheckout < Minitest::Test
 
   def test_that_bogof_applied_with_odd_number
     5.times do
-      @checkout.add(:ZERO2W)
+      @checkout.add(:ZERO2W) # Should still remove 2 Zeros, 5th is full price
     end
 
     assert_equal 45.00, @checkout.total
   end
+
+  def test_that_price_is_reduced_for_3_picos
+    3.times do
+      @checkout.add(:PICO2) # 3.50 * 3 = 10.50
+    end
+
+    assert_equal 10.50, @checkout.total
+  end
+
+  def test_that_price_is_reduced_for_more_than_3_picos
+    4.times do
+      @checkout.add(:PICO2) # 3.50 * 4 = 14
+    end
+
+    assert_equal 14.00, @checkout.total
+  end
+
+  def test_that_price_is_not_reduced_for_less_than_3_picos
+    2.times do
+      @checkout.add(:PICO2)
+    end
+
+    assert_equal 8.00, @checkout.total
+  end
+
+  def test_that_both_discounts_apply_at_the_same_time
+    4.times do
+      @checkout.add(:ZERO2W) # 30.00 total
+    end
+
+    3.times do
+      @checkout.add(:PICO2) # 10.50 total
+    end
+
+    assert_equal (30.00 + 10.50), @checkout.total
+  end
 end