Form Template Method.

form-template-method/lib/after.rb

@@ -0,0 +1,28 @@
+class Ticket
+  attr_reader :price
+
+  def initialize
+    @price = 2.0
+  end
+
+  def price *args
+    @price * discount
+  end
+
+  def discount
+    1
+  end
+
+end
+
+class SeniorTicket < Ticket
+  def discount
+    0.75
+  end
+end
+
+class JuniorTicket < Ticket
+  def discount
+    0.5
+  end
+end

form-template-method/lib/before.rb

@@ -0,0 +1,20 @@
+class Ticket
+  attr_reader :price
+
+  def initialize
+    @price = 2.0
+  end
+
+end
+
+class SeniorTicket < Ticket
+  def price
+    @price * 0.75
+  end
+end
+
+class JuniorTicket < Ticket
+  def price
+    @price * 0.5
+  end
+end

form-template-method/test/test.rb

@@ -3,3 +3,18 @@
 
 require 'before' if ENV["BEFORE"]
 require 'after' unless ENV["BEFORE"]
+
+describe Ticket do
+  it "has a calculated price" do
+    Ticket.new.price.must_equal 2.0
+  end
+
+  it "costs less if a senior" do
+    SeniorTicket.new.price.must_equal 1.5
+  end
+
+  it "costs less if a junior" do
+    JuniorTicket.new.price.must_equal 1.0
+  end
+
+end