Extract Class.

extract-class/lib/after.rb

@@ -0,0 +1,54 @@
+class Student
+
+  attr_reader :terms
+
+  def initialize
+    @terms = [
+      Term.new(:first),
+      Term.new(:second),
+      Term.new(:third)
+    ]
+  end
+
+  def set_all_grades_to grade
+    terms.each { |term| term.set_all_grades_to(grade) }
+  end
+
+  def first_term_grade
+    term(:first).grade
+  end
+
+  def second_term_grade
+    term(:second).grade
+  end
+
+  def third_term_grade
+    term(:third).grade
+  end
+
+  def term reference
+    terms.find { |term| term.name == reference }
+  end
+end
+
+class Term
+
+  attr_reader :name, :assiduity, :test, :behavior
+
+  def initialize name
+    @name      = name
+    @assiduity = 0
+    @test      = 0
+    @behavior  = 0
+  end
+
+  def set_all_grades_to grade
+    @assiduity = grade
+    @test      = grade
+    @behavior  = grade
+  end
+
+  def grade
+    (assiduity + test + behavior) / 3
+  end
+end

extract-class/lib/before.rb

@@ -0,0 +1,25 @@
+class Student
+  attr_accessor :first_term_assiduity, :first_term_test, :first_term_behavior
+  attr_accessor :second_term_assiduity, :second_term_test, :second_term_behavior
+  attr_accessor :third_term_assiduity, :third_term_test, :third_term_behavior
+
+  def set_all_grades_to grade
+    %w(first second third).each do |which_term|
+      %w(assiduity test behavior).each do |criteria|
+        send "#{which_term}_term_#{criteria}=".to_sym, grade
+      end
+    end
+  end
+
+  def first_term_grade
+    (first_term_assiduity + first_term_test + first_term_behavior) / 3
+  end
+
+  def second_term_grade
+    (second_term_assiduity + second_term_test + second_term_behavior) / 3
+  end
+
+  def third_term_grade
+    (third_term_assiduity + third_term_test + third_term_behavior) / 3
+  end
+end

extract-class/test/test.rb

@@ -3,3 +3,14 @@
 
 require 'before' if ENV["BEFORE"]
 require 'after' unless ENV["BEFORE"]
+
+describe Student do
+  it "has a grade for all three terms" do
+    student = Student.new
+    student.set_all_grades_to 10
+
+    student.first_term_grade.must_equal 10
+    student.second_term_grade.must_equal 10
+    student.third_term_grade.must_equal 10
+  end
+end